Split from this thread.

I have the same issue. My Outlook has crashed several times over the past few months and I've lost all sorts of email due to corruption of my identities.

I've rebuilt identities several times to no avail. 

Again for the past two days I'm getting a "Syntax error in arguments" Error code 17099 in one of my email accounts. 

I've tried deleting and reinstalling and still having issues from Office 365. 

I've also noticed the Word and Excel act up badly as well.