As I saw that the 6.2.0 stable release was here, I wanted to update my unRAID server. As per the recommended way I check for updates in the plugin screen and decided to first apply the updates of all other plugins to minimise compatibility issues. I then updated the unRAID OS itself.
In the update of unRAID OS itself, somehow something went wrong. I don't have a screenshot and can't recall it specifically but I saw an error which mentioned problems copying a file (using copy() function).
With the update applied badly, almost all screens in the webGUI were now blank.