Using Outlook 2019 with IMAP Email. When I try to archive I see an error message pointing me to the deleted items folder. There I find a message: Error while archiving folder "Banking" in store "firstname.lastname@example.org". The destination folder contains items of a different type than the source folder. Verify both the source and destination folders contain the same types of items.
The IMAP source folder contains simple Emails, as does the archive folder on my hard disk. Some folders do archive OK, and as far as I can see the data type, etc, is just the same as on folders which won't archive. Any help gratefully received.