I recently reinstalled windows on my PC and with it installed Python (with the Anaconda Navigator). I also installed miniconda (on my user) and set up a new environment, installed all my packages there, including Qt5 and PyQt5.

When lunching the affected script in spyder (other scripts worked) or running it, in my environment, I get this error message pop-up:

This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

I tried:

• Un- and reinstalling PyQt5 and Qt in my environment
• Follow this solution but it didn’t work out:
  I added this to the PATH variable in the system and in the user variable, because I installed miniconda on my user. I had a hard time locating the correct paths. The first one, in my case was:

1. C:Usersuserminiconda3envsnew_envLibsite-packagesPyQt5Qt5bin

Problematic was, locating the last two paths within the PyQt5 folder. There simply is no “plugins” folder in Qt5. Instead, I used these paths:

2. C:Usersuserminiconda3envsnew_envLibraryplugins
3. C:Usersuserminiconda3envsnew_envLibrarypluginsplatforms

or
2. C:Usersuserminiconda3envsnew_envLibrarypluginsPyQt5

• locating pyqt5_tools to copy the platforms folder – I couldn’t find such a folder on my whole C: drive.

I really don’t know what to do and I am not too familiar with the PATH variable and miniconda. Help is highly appreciated.