Shared Mailboxes on MS, removal kills the account in emClient

Hi,

I added a shared mailbox to one of my MS accounts, added it in Delegation to emClient. When I remove the shared mailbox I get EWS An error occurred, no other details.

Tried removing then adding the email account then adding it back in and it got worse, now it will not retrieve any account folder/emails or any other detail.

Any help welcome.
Michael.