No Qt platform plugin could be initialized

jsulm

@Tom_B said in No Qt platform plugin could be initialized:

ould like to upgrade current qt installation

If you already have a Qt installation then you can simply use the Qt maintenance tool to install/remove Qt versions and tools.

Tom_B

Unfortunately, neither current installer nor the Qt maintanance work. Only old versions of both, as I wrote. I have been using Qt more than 10 years, but this never happened to me.

Tom_B

I deleted the Qt folder content. Now, I am able to run

qt-unified-windows-x64-4.6.1-online.exe

and install Qt. However, trying to use Qt maintenance tool, the above mentioned error occurs.

hskoglund

You coild try installing Qt as another user on your desktop (via Settings, Accounts, Other Users, click "Add account")

Tom_B

Installation as a new user as well as Qt maintanance SW work well. After the user is switched to the old one, the same error occurs.

Tom_B

The same issue on my notebok with Win11. After unistalling old version of Qt, the new installator throws the same error. Probably some remaining hidden settings, lost items in registry or environments settings?

jeremy_k

Setting the environment variable QT_DEBUG_PLUGINS to a non-zero value should result in information about the platform plugin loading to be dumped to the console. Sometimes it provides very direct and actionable feedback, eg reporting a missing dependency or version mismatch.

Using QT_WIN_DEBUG_CONSOLE is probably also necessary.

Further documentation: https://doc.qt.io/qt-6/debug.html#environment-variables-recognized-by-qt

Tom_B

Thank you very much for your comment. I set both varibles to 1 in both sections, User variables and System variables, restated the PC. However, the qt installator threw the same error code and did not start.

Tom_B

I found the solution. Deleting the User/System variable

QT_QPA_PLATFORM_PLUGIN_PATH
c:\Users\Tomas\AppData\Roaming\Python\Python36\site-packages\PyQt6\Qt6\plugins\platforms

solved the problem. Probably this value is a residual from a previous installation that was not removed. The new installator is sensitive to this item.

jeremy_k

@Tom_B said in No Qt platform plugin could be initialized:

Thank you very much for your comment. I set both varibles to 1 in both sections, User variables and System variables, restated the PC. However, the qt installator threw the same error code and did not start.

QT_WIN_DEBUG_CONSOLE expects a value of new or attach. 1 is probably the same as not setting it.