I upgraded to 4.5 today and now when I run tools -> run manage.py task it says "fetching django commands" with a progress bar, then dies with the error "Failed to get real commands on module <modulename>, python process died with code 0: unknown error.
It does pop open the "new?" manage.py@<modulename> window down below, and running tasks there seems to work ok. I've restarted the application but the error still appears. So I can no longer use the popup window for run manage.py task.