Addtional debugging info: Debugging turned out that calItipUtils.jsm (@ line 202) did not find any writable calendars.
Currently I uninstalled Thunderbird, cleaned up any cached data and reinstalled Thunderbird. It doesn't work for me.
Addtional debugging info:
Debugging turned out that calItipUtils.jsm (@ line 202) did not find any writable calendars.
Currently I uninstalled Thunderbird, cleaned up any cached data and reinstalled Thunderbird. It doesn't work for me.