Hi all, for those of us who use Python's IDLE for developing: there is a known bug in Python 3.8.4 (issue 41300) which sometimes prevents saving a script file. Not sure whether this is Windows only. To solve this you may - use another editor - add a BOM to the file , e. g. via notepad++ but do never submit such files to pywikibot repository - use Python 3.8.3 instead - or (my preferred solution) modify the related Python 3.8.4 file: look for the Python installation. Open the iomenu.py inside Lib/idlelib folder and add the line "import io" (without quotes) on top of this file. Best xqt