Problem with deploying Qt/C++ desktop app that uses Qt Charts library

whatisjeff

Hello, I'm having trouble deploying a Qt/C++ application to another computer. There seems to be a problem with using the charts library. In one test application, it doesn't use that library, so it doesn't include the Qt5Charts.dll, and it works perfectly. The other one does, and it gives the message "could not find or load the Qt platform plugin 'windows'" even though the qwindows.dll is with the application. Please help!

ChrisW67

The qwindows.dll should be in a sub-directory "platforms" adjacent to the application executable. The error has nothing to do with Qt Charts.

podsvirov

Have you read the documentation on deployment of applications?
Read there: "Deploying Qt Applications":http://doc.qt.io/qt-5/deployment.html

JKSH

[quote author="Konstantin Podsvirov" date="1420876109"]Have you read the documentation on deployment of applications?
Read there: "Deploying Qt Applications":http://doc.qt.io/qt-5/deployment.html[/quote]...and also the following wiki: http://qt-project.org/wiki/Deploy_an_Application_on_Windows

!http://i.imgur.com/S582DlV.png(DLL locations)!

whatisjeff

Yes, I should mention that qwindows.dll is in a "platforms" directory. When the executable is opened, an error like this pops up:

"
This application failed to start because it could not find or load the Qt platform plugin "windows".

Platforms available: "windows"

Reinstalling the application may fix this problem
"

And yes I've read both of those guides

SGaist

Hi and welcome to devnet,

Maybe a silly question but, did you build your library in release mode ?

JKSH

[quote author="whatisjeff" date="1420919498"]"This application failed to start because it could not find or load the Qt platform plugin "windows".

Platforms available: "windows"[/quote]Qt said that the "windows" platform is available but can't be loaded. That usually means that one or more of the dependencies of qwindows.dll is missing.

Which steps did you follow under Initial deployment (Quick and dirty) in http://qt-project.org/wiki/Deploy_an_Application_on_Windows ?

Another possible reason (though I'm less sure about this one) is that you used the wrong version of the qwindows.dll or one of its dependencies. Make sure all of your DLLs match your kit (e.g. if you compiled your application with 32-bit MinGW 4.9.1, then make sure you get all your DLLs from _...\mingw491_32\bin_ and _...\mingw491_32\plugins_).