Application failed to start because it could not find or load the QT platform plugin "windows"
c++, dll, platform, qt
Solution
Well I solved my issue, although I'm not sure what the difference is:
I copied every dll from my qt directory into both ./ and ./platforms of my application directory.
The application got past the error, but then crashed.
VERSION.dll was causing the crash (noted in dependency walker), so I removed it from both places.
The Application started up, so I systematically removed all unneeded dll's.
This got me back to the same state I had originally.
I then uninstalled my application and re-installed (with only the ./platforms/qwindows.dll file remaining), application works correctly.
So all I can assume is that I had an incorrect version of qwindows.dll in the platforms directory.
Problem
I have looked through all of the questions that appear to be related on stack overflow, and none of the solutions seem to help me. I am building a Qt application with this setup: - Windows 7 Professional x64 - Visual Studio 2012 - Qt 5.2.0 built with `configure -developer-build -debug-and-release -opensource -nomake examples -nomake tests -platform win32-msvc2012 -no-opengl` - Project uses QtSingleApplication (qt-solutions) - Application is a 32 bit application - qmake run with the following: -makefile -spec win32-msvc2012 - .pri uses `QMAKE_CXX += /D_USING_V110_SDK71_` I can build and run my program fine on my development machine (noted above); I can also install and run the package from Program Files directory on dev machine. When I install and run on a Windows Vista machine (multiple machines) - VC++ redist 2012 11.0.61030.0 installed - VC++ redist 2010 10.0.40219 installed - plus 2005, 2008 versions of redist (also fails on a clean install of Windows 7) I get: `Application failed to start because it could not find or load the QT platform plugin "windows"` So I followed the instructions and added a .platforms/ directory, and added qwindows.dll (also added qminimal.dll and qoffscreen.dll); I also added libEGL.dll, libGLESv2.dll (even though I shouldn't need them I don't think) Once I added qoffscreen.dll I now get the additional message: `Available platform plugins are: offscreen` If I run through Dependency Walker I get this error listed: ``` GetProcAddress(0x76CA0000 [KERNEL32.DLL], "GetCurrentPackageId") called from "MSVCR110.DLL" at address 0x6AC6FDFA and returned NULL. Error: The specified procedure could not be found (127). ``` and then further down get the: ``` GetProcAddress(0x745A0000 [UXTHEME.DLL], "BufferedPaintUnInit") called from "COMCTL32.DLL" at address 0x745FFBF8 and returned 0x745AE18C. This application failed to start because it could not find or load the Qt platform plugin "windows". Available platform plugins are: offscreen. Reinstalling the application may fix this problem. ``` Any ideas how to fix this dll issue?