Can't load windows plugin

Qatto

I was able to build my application but can't deploy it anywhere else other than the development pc.
The application produces the following output on crashing:

@Problem Event Name: APPCRASH
Application Name: theApp.exe
Application Version: 0.0.0.0
Application Timestamp: 526faf5c
Fault Module Name: Qt5Core.dll
Fault Module Version: 5.0.1.0
Fault Module Timestamp: 51082eed
Exception Code: 40000015
Exception Offset: 0000dc55@

I run dependency walker on a new machine and profiled the application which produced this error yet my app includes qwindows.dll in the platforms directory.

@LoadLibraryW("C:\program files\theapp\platforms\qwindows.dll") returned NULL. Error: The specified procedure could not be found (127).
Failed to load platform plugin "windows". Available platforms are:
windows@

Am wondering why it's failing to find qwindows.dll

zibicoder

Try this:
@LoadLibraryW("C:\program files\theapp\platforms\qwindows.dll")@
or:
@LoadLibraryW("C:/program files/theapp/platforms/qwindows.dll")@

Qatto

Thanks zibicoder for the reply. Should I write this in the applications source code, and where should I place it?

zibicoder

On the clear machine (without Qt instalation) you should put your app in one folder with all *.dll's needed (e.g. QtGui.dll, QtWidgets.dll, etc). In this same folder you should put folder "platforms" with qwindows.dll, folder printsupport with its dll's and so on). I dont know, what is your app and which libraries of Qt it needs exactly.

Qatto

Yes, that's what I have been doing all along. But the executable can't load it from the platforms directory.

zibicoder

Sorry, i don't understood your firs post. The line "LoadLibraryW(..." it is message from Dependency Walker, isn't it? I have no idea, why it dont work. Maby it is problem with location your folder with app on C:\ (problem UAC in windows?) I utilize method desribed below and i havn't problems yet, but my default localisation of apps is logical disk d:\programms. Let search forums for similar threads, perhaps you'll find the ansver.
Best regards.

mrdebug

In the past I have had the same problem (using mingw).
If you want you can download this package
http://www.denisgottardello.it/BackupTo/BackupTo.php
and look at the dlls and plugins. Remember that you have to specify the plusing location using qt.conf special file.

Qatto

Dependency walker indicates that the fault is coming from the qt_plugin_query_metadata function inside qwindows.dll. So the plugin is seen by the application but it cannot be loaded. What causes this?