solved: Could not load the Qt platform plugin "xcb"

[ljubomirb]

I will leave here solution for a problem that I could not fix for days, hope it would help someone:
So, the error was:

QObject::moveToThread: Current thread (...) is not the object's thread (...).
Cannot move to target thread (...)
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/(...)site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

I was trying hard, but could not fix it. I was downloading literally hundreds of different packages, over and over again, trying all sorts of "hacks" found online, eventually trying anaconda, a massive download...
In the end, I don't know if that was the fix, because my system is about to be reinstalled after all of my "trying", BUT, after I wrote this in console:
export QT_QPA_PLATFORM=offscreen
everything worked.
Again, don't know if this was solution OR any of hundreds of packages installed, but try this first. If it works, maybe add this to Q&A .
Good luck!

[Tom94]

Hi there, thanks for reporting. This seems to have been a problem with the cv2 Python package and how it loops in Qt -- the instant-ngp codebase itself doesn't actually use Qt anywhere. Cheers!