This is a known bug, and a fix was already committed.
However, the fix was reversed, as it apparently caused some problems on KiCad Installations (I think it’s for the people who still use Python2.)
You can get to the fix by following:
Which links to:
If you compare it with other commits, you will find references to the “PadArrayGrid, self” text in about 5 or 6 different locations.