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this application failed to start because it could not find or load the Qt platform plugin “windows” in “” when running exe



  • I have been spinning my wheels here and have not found the correct answer to this. I created my application in Python and ran fbs_freeze using the fman system. which created my target folder and the .exe file. When I try to run the .exe file, I receive this error:
    2020-09-23 21_45_15-scales (Debugging) - Microsoft Visual Studio.png

    this application failed to start because it could not find or load the Qt platform plugin "windows" in "" pyqt5 fbs exe

    It looks like it is finding qwindow.dll but then unloads it. I can also confirm the files exist in the paths in the debug print out.

    I am on a windows 10 laptop. I have been all over the internet and in numerous threads to resolve this and have confirmed nothing in my PATH variable is referring to qwindow etc...

    Any ideas on how to fix this or steps to troubleshoot?



  • @dgrz1985
    As every single time anyone gets this error, same starting point: from Command Prompt, set QT_DEBUG_PLUGINS=1, run your application, look at the end of the diagnostic output.



  • @JonB Well apparently what you recommended does not work on Windows per this thread: https://forum.qt.io/topic/41943/platform-plugin-windows/8 . However, I used DebugView as referenced in that article. Here is the image of the end where it terminates. I can tell you right now, I navigate right to the path it refers to and see the qwindows.dll file. app_debug.png



  • @dgrz1985
    I don't use Qt under Windows so I can't say what is/is not necessary. By the sound of it, the easiest would be to run it through Qt Creator setting the Run Environment to have that variable set, if you say it does not work from command line.

    Anyway, your output is somewhat curtailed, there are some references in there to why it cannot load the qwindows.dll. A "specified procedure cannot be found" might indicate some version mismatch between what you have and what is expected, I don't know. You might glean more information if you run a Dependency Viewer on qwindows.dll.

    That's all I know. You might be able to Google for why qwindows.dll is not working for you. Or they may be other people here using Windows who can answer.


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