This issue was solved 1.5 y ago: Accepting invitation tries to create an event in RO shared calendar
But since recently we are encountering the same issue (for detailed explanation please have a look at the mentioned issue) again. But it only fails if the invitation comes from a Microsoft Teams Account. Other invitations still working fine.
What I observed is that the MS invitation mail does not contain an .ics file (anymore?!). At least not as an attached plain text file. Instead the mail containes the ics as a base64 coded invisible part of the mail. This obviously circumvents the fix that was implemented for the “RO shared calendar” issue in version 10.3.1720 and eMClient is looking for an already existing duplicate event even in RO shared calendars (again) and tries to update the existing one which is forbidden because the containing shared calendar is RO.
Could someone of the eMClient Team please have a look at this (again)? Thanks a lot!