EWS Sync Error - cannot send or receive messages after initial Sync

[Exchange Web Services]Synchronizing folder ‘xxxxx@xxxxxxx.com/Inbox’ failed due to the following error: ‘’, hexadecimal value 0xFFFF, is an invalid character. Line 3254, position 33.

What version of eM Client are you running and do you have Windows or Mac ?.

Also did you setup via the automatic email wizard in eM Client or manual option ?

Lastly have you tried closing and reopening eM Client and rebooting your computer ?

1/ Running version 8.2.1659 (845a639) on Windows 10
2/ have tried via automatic and Manual. Sync works using IMAP, but i lose calendar and contacts
3/ Yes, I have rebooted and stopped/Restarted emlient several times.

Have you tried eM Client with (Exchange setup) instead IMAP setup.

https://www.emclient.com/em-with-microsoft-exchange