Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. could not find or load the Qt platform plugin "windows" in "".
Forum Updated to NodeBB v4.3 + New Features

could not find or load the Qt platform plugin "windows" in "".

Scheduled Pinned Locked Moved Unsolved General and Desktop
20 Posts 8 Posters 11.4k Views 4 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • P Pixijayne

    Is this Qt Windows 'thing' a totally separate 'thing' that needs installing, on my system ?

    Or should it be contained within the UO Steam prog ?

    Pl45m4P Offline
    Pl45m4P Offline
    Pl45m4
    wrote on last edited by Pl45m4
    #7

    @Pixijayne

    I think your game or game launcher uses Qt for some GUI and your exe points to the directory where the required Qt stuff should be located. If you move your exe without creating a shortcut or link, the paths are not correct anymore.
    Normally re-installing the game completely should fix it.

    It's the same when deploying your own app that uses Qt. You need the qt files, otherwise your program doesn't work outside your development environment.

    @Pixijayne said in could not find or load the Qt platform plugin "windows" in "".:

    Is this Qt Windows 'thing' a totally separate 'thing' that needs installing, on my system ?

    and no, you don't need to install Qt by yourself. If the game launcher from your game uses Qt, all the related stuff comes with the game. This is exactly your problem. It looks like the game can't find its Qt files

    Maybe this helps
    https://forum.qt.io/topic/90293/could-not-find-or-load-the-qt-platform-plugin-windows-in


    If debugging is the process of removing software bugs, then programming must be the process of putting them in.

    ~E. W. Dijkstra

    1 Reply Last reply
    2
    • P Offline
      P Offline
      Pixijayne
      wrote on last edited by
      #8

      Ok .. Im still stuck

      I have uninstall both the game and the launcher ..

      Reinstalled to a portable HDD and I still have the same problem

      Pl45m4P 1 Reply Last reply
      0
      • P Pixijayne

        Ok .. Im still stuck

        I have uninstall both the game and the launcher ..

        Reinstalled to a portable HDD and I still have the same problem

        Pl45m4P Offline
        Pl45m4P Offline
        Pl45m4
        wrote on last edited by
        #9

        @Pixijayne

        Check the Qt_PATH variable, like suggested in that linked thread. Is it empty?


        If debugging is the process of removing software bugs, then programming must be the process of putting them in.

        ~E. W. Dijkstra

        P 1 Reply Last reply
        0
        • R Offline
          R Offline
          Rondog
          wrote on last edited by Rondog
          #10

          You are probably missing some files (the platform plugin folder for sure). When I distribute an application it has a layout something like this:

          ├── Qt5Core.dll
          ├── Qt5Gui.dll
          ├── Qt5Widgets.dll
          ├── application.exe
          ├── libgcc_s_seh-1.dll
          ├── libstdc++-6.dll
          ├── libwinpthread-1.dll
          └── platforms
              ├── qdirect2d.dll
              ├── qminimal.dll
              ├── qoffscreen.dll
              └── qwindows.dll
          

          Note: Some files in the above list such as libgcc_s_seh-1.dll, libstdc++-6.dll, and libwinpthread-1.dll are a result of the compiler you are using. I am using MinGW64 and those files are required as a result. You list will probably be different but you will still need the platforms subfolder and contents.

          P 1 Reply Last reply
          0
          • Pl45m4P Pl45m4

            @Pixijayne

            Check the Qt_PATH variable, like suggested in that linked thread. Is it empty?

            P Offline
            P Offline
            Pixijayne
            wrote on last edited by
            #11

            @Pl45m4 I did try to .. here are the results ..

            Microsoft Windows [Version 10.0.18362.657]
            (c) 2019 Microsoft Corporation. All rights reserved.

            C:\Windows\System32>echo %QT_PLUGIN_PATH%
            %QT_PLUGIN_PATH%

            C:\Windows\System32>

            Microsoft Windows [Version 10.0.18362.657]
            (c) 2019 Microsoft Corporation. All rights reserved.

            C:\Windows\System32>echo %PATH%
            C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\WIDCOMM\Bluetooth Software;C:\Program Files\WIDCOMM\Bluetooth Software\syswow64;C:\Program Files\nodejs;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0;C:\Program Files\WorldPainter;C:\Program Files (x86)\Skype\Phone;C:\WINDOWS\System32\OpenSSH;C:\Program Files (x86)\EaseUS\Todo Backup\bin;C:\Program Files (x86)\Common Files\Acronis\SnapAPI;C:\Users\Administrator\AppData\Roaming\npm;%USERPROFILE%\AppData\Local\Microsoft\WindowsApps;C:\Program Files (x86)\EaseUS\Todo Backup\bin\x64\

            C:\Windows\System32>

            1 Reply Last reply
            0
            • R Rondog

              You are probably missing some files (the platform plugin folder for sure). When I distribute an application it has a layout something like this:

              ├── Qt5Core.dll
              ├── Qt5Gui.dll
              ├── Qt5Widgets.dll
              ├── application.exe
              ├── libgcc_s_seh-1.dll
              ├── libstdc++-6.dll
              ├── libwinpthread-1.dll
              └── platforms
                  ├── qdirect2d.dll
                  ├── qminimal.dll
                  ├── qoffscreen.dll
                  └── qwindows.dll
              

              Note: Some files in the above list such as libgcc_s_seh-1.dll, libstdc++-6.dll, and libwinpthread-1.dll are a result of the compiler you are using. I am using MinGW64 and those files are required as a result. You list will probably be different but you will still need the platforms subfolder and contents.

              P Offline
              P Offline
              Pixijayne
              wrote on last edited by
              #12

              @Rondog I have uninstalled and reinstalled the launcher ... I have also copied a working copy, from another PC to this PC and its giving the same error. Here is a screenshot of the dir .. there is a Platforms dir and it has one file/.dll in it - qwindows.dll

              I am so in over my head, thank you guys for trying to help path II.PNG

              JKSHJ 1 Reply Last reply
              0
              • J Offline
                J Offline
                Jackson Leee
                wrote on last edited by
                #13

                @Pixijayne said in could not find or load the Qt platform plugin "windows" in "".:

                Is this Qt Windows 'thing' a totally separate 'thing' that needs installing, on my system ?
                Or should it be contained within the UO Steam prog ?

                I'm thinking whether it is a Windows system problem?.....
                Or have you tried deleting unnecessary residual directories and trying again?....

                1 Reply Last reply
                0
                • P Pixijayne

                  @Rondog I have uninstalled and reinstalled the launcher ... I have also copied a working copy, from another PC to this PC and its giving the same error. Here is a screenshot of the dir .. there is a Platforms dir and it has one file/.dll in it - qwindows.dll

                  I am so in over my head, thank you guys for trying to help path II.PNG

                  JKSHJ Offline
                  JKSHJ Offline
                  JKSH
                  Moderators
                  wrote on last edited by
                  #14

                  @Pixijayne said in could not find or load the Qt platform plugin "windows" in "".:

                  ... I have also copied a working copy, from another PC to this PC and its giving the same error.

                  My guess is that something in your latest PC's environment is interfering with Qt.

                  If one of the folders in your PATH contain Qt DLLs, for example, that can cause UOS to try to load the DLL from the wrong folder, which then fails because the different versions of the DLLs are not compatible.

                  Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                  P 1 Reply Last reply
                  1
                  • P Pixijayne

                    I am trying to run a 3rd party game launcher called UO Steam, to run the game Ultima Online.

                    I have 3 PCs running it ATM and my son wants to play too so I was trying to run it on a 4th/his.

                    I'm getting an error msg:

                    This application failed to start because it could not find or load the Qt platform plugin "windows" in "".
                    Reinstalling the application may fix this problem.

                    I am running it in Admin Mode

                    I have done an SFC and

                    DISM.exe /Online /Cleanup-image /Scanhealth

                    DISM.exe /Online /Cleanup-image /Restorehealth

                    I have removed UOS and reinstalled - I even rebooted the bloody PC shezzzzz what else can I do ?!?!?!?!?

                    On the C drive I found an empty dir called .QtWebEngineProcess

                    I am at a total loss on how to even tackle this issue.

                    J.HilkJ Offline
                    J.HilkJ Offline
                    J.Hilk
                    Moderators
                    wrote on last edited by
                    #15

                    @Pixijayne question, do your pc (and the other's where its working) have different version of windows on it?


                    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                    Q: What's that?
                    A: It's blue light.
                    Q: What does it do?
                    A: It turns blue.

                    1 Reply Last reply
                    0
                    • JKSHJ JKSH

                      @Pixijayne said in could not find or load the Qt platform plugin "windows" in "".:

                      ... I have also copied a working copy, from another PC to this PC and its giving the same error.

                      My guess is that something in your latest PC's environment is interfering with Qt.

                      If one of the folders in your PATH contain Qt DLLs, for example, that can cause UOS to try to load the DLL from the wrong folder, which then fails because the different versions of the DLLs are not compatible.

                      P Offline
                      P Offline
                      Pixijayne
                      wrote on last edited by
                      #16

                      @JKSH .. How difficult is it to workout if/what its is a PATH issue ....

                      @J-Hilk .. Both running Win 10 Pro ....

                      1 Reply Last reply
                      0
                      • SGaistS Offline
                        SGaistS Offline
                        SGaist
                        Lifetime Qt Champion
                        wrote on last edited by
                        #17

                        Hi,

                        Use the command line to start your application. There you can modify the PATH environment variable for that session only and remove each entry one after the other until your application works or it's empty and there's something else at play.

                        Interested in AI ? www.idiap.ch
                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                        1 Reply Last reply
                        0
                        • R Offline
                          R Offline
                          Rondog
                          wrote on last edited by
                          #18

                          You could turn on the plugin debug option and see what it says. You need to set the environment variable QT_DEBUG_PLUGINS to a non-zero value and compile your program with the 'console' option set. When you run it from a terminal window you should see something like this:

                          c:\MyProjects\downloadeditor>cd bin
                          
                          c:\MyProjects\downloadeditor\bin>downloadeditor
                          QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/platforms" ...
                          QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qdirect2d.dll"
                          Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qdirect2d.dll, metadata=
                          {
                              "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                              "MetaData": {
                                  "Keys": [
                                      "direct2d"
                                  ]
                              },
                              "archreq": 0,
                              "className": "QWindowsDirect2DIntegrationPlugin",
                              "debug": false,
                              "version": 331008
                          }
                          
                          
                          Got keys from plugin meta data ("direct2d")
                          QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qminimal.dll"
                          Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qminimal.dll, metadata=
                          {
                              "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                              "MetaData": {
                                  "Keys": [
                                      "minimal"
                                  ]
                              },
                              "archreq": 0,
                              "className": "QMinimalIntegrationPlugin",
                              "debug": false,
                              "version": 331008
                          }
                          
                          
                          Got keys from plugin meta data ("minimal")
                          QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qoffscreen.dll"
                          Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qoffscreen.dll, metadata=
                          {
                              "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                              "MetaData": {
                                  "Keys": [
                                      "offscreen"
                                  ]
                              },
                              "archreq": 0,
                              "className": "QOffscreenIntegrationPlugin",
                              "debug": false,
                              "version": 331008
                          }
                          
                          
                          Got keys from plugin meta data ("offscreen")
                          QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll"
                          Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll, metadata=
                          {
                              "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                              "MetaData": {
                                  "Keys": [
                                      "windows"
                                  ]
                              },
                              "archreq": 0,
                              "className": "QWindowsIntegrationPlugin",
                              "debug": false,
                              "version": 331008
                          }
                          
                          
                          Got keys from plugin meta data ("windows")
                          loaded library "C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll"
                          QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/platformthemes" ...
                          QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/styles" ...
                          QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/iconengines" ...
                          QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/imageformats" ...
                          QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/accessible" ...
                          QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/accessiblebridge" ...
                          QLibraryPrivate::unload succeeded on "C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll"
                          
                          c:\MyProjects\downloadeditor\bin>
                          

                          You can set the environment variable from the Control Panel - System - Environment Variables option (Win7). The console option is set in the PRO file and it looks like this in this example:

                          CONFIG +=	release \
                          		warn_on \
                          		qt \
                          		thread \
                          		console
                          

                          You will need to run qmake and probably clean everything. I tried it without adding the console option to the pro file and it didn't do anything.

                          Pl45m4P 1 Reply Last reply
                          0
                          • R Rondog

                            You could turn on the plugin debug option and see what it says. You need to set the environment variable QT_DEBUG_PLUGINS to a non-zero value and compile your program with the 'console' option set. When you run it from a terminal window you should see something like this:

                            c:\MyProjects\downloadeditor>cd bin
                            
                            c:\MyProjects\downloadeditor\bin>downloadeditor
                            QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/platforms" ...
                            QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qdirect2d.dll"
                            Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qdirect2d.dll, metadata=
                            {
                                "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                                "MetaData": {
                                    "Keys": [
                                        "direct2d"
                                    ]
                                },
                                "archreq": 0,
                                "className": "QWindowsDirect2DIntegrationPlugin",
                                "debug": false,
                                "version": 331008
                            }
                            
                            
                            Got keys from plugin meta data ("direct2d")
                            QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qminimal.dll"
                            Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qminimal.dll, metadata=
                            {
                                "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                                "MetaData": {
                                    "Keys": [
                                        "minimal"
                                    ]
                                },
                                "archreq": 0,
                                "className": "QMinimalIntegrationPlugin",
                                "debug": false,
                                "version": 331008
                            }
                            
                            
                            Got keys from plugin meta data ("minimal")
                            QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qoffscreen.dll"
                            Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qoffscreen.dll, metadata=
                            {
                                "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                                "MetaData": {
                                    "Keys": [
                                        "offscreen"
                                    ]
                                },
                                "archreq": 0,
                                "className": "QOffscreenIntegrationPlugin",
                                "debug": false,
                                "version": 331008
                            }
                            
                            
                            Got keys from plugin meta data ("offscreen")
                            QFactoryLoader::QFactoryLoader() looking at "C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll"
                            Found metadata in lib C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll, metadata=
                            {
                                "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
                                "MetaData": {
                                    "Keys": [
                                        "windows"
                                    ]
                                },
                                "archreq": 0,
                                "className": "QWindowsIntegrationPlugin",
                                "debug": false,
                                "version": 331008
                            }
                            
                            
                            Got keys from plugin meta data ("windows")
                            loaded library "C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll"
                            QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/platformthemes" ...
                            QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/styles" ...
                            QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/iconengines" ...
                            QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/imageformats" ...
                            QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/accessible" ...
                            QFactoryLoader::QFactoryLoader() checking directory path "C:/MyProjects/downloadeditor/bin/accessiblebridge" ...
                            QLibraryPrivate::unload succeeded on "C:/MyProjects/downloadeditor/bin/platforms/qwindows.dll"
                            
                            c:\MyProjects\downloadeditor\bin>
                            

                            You can set the environment variable from the Control Panel - System - Environment Variables option (Win7). The console option is set in the PRO file and it looks like this in this example:

                            CONFIG +=	release \
                            		warn_on \
                            		qt \
                            		thread \
                            		console
                            

                            You will need to run qmake and probably clean everything. I tried it without adding the console option to the pro file and it didn't do anything.

                            Pl45m4P Offline
                            Pl45m4P Offline
                            Pl45m4
                            wrote on last edited by Pl45m4
                            #19

                            @Rondog

                            It's not OP's project. @Pixijayne is an end user who's trying to play / install a game, which is using Qt. So there is no code available.


                            If debugging is the process of removing software bugs, then programming must be the process of putting them in.

                            ~E. W. Dijkstra

                            R 1 Reply Last reply
                            1
                            • Pl45m4P Pl45m4

                              @Rondog

                              It's not OP's project. @Pixijayne is an end user who's trying to play / install a game, which is using Qt. So there is no code available.

                              R Offline
                              R Offline
                              Rondog
                              wrote on last edited by
                              #20

                              @Pl45m4 Yeah, I missed that detail.

                              1 Reply Last reply
                              0

                              • Login

                              • Login or register to search.
                              • First post
                                Last post
                              0
                              • Categories
                              • Recent
                              • Tags
                              • Popular
                              • Users
                              • Groups
                              • Search
                              • Get Qt Extensions
                              • Unsolved