Outlook for Mac 15.3 (Outlook 365) gets hung up on Sync Pending

I "upgraded" and still same problem - the dreaded "Sync Pending for this folder" remains. I have a msn account.

I've long given up on Outlook, and subscribe to this thread to see merely how many people have to say something for Microsoft to actually do something, or even acknowledge a problem. 

And by the way - what is with outlook for mac always asking whether i want to re-enter my password when not connected to the internet (when i'm commuting for example). Absolutely infuriating. why doesn't it just realise i'm offline? Grrrr....

Thanks for advise. The sync errors is primarily from shared calendar events in my team, so cant delete those.

I have exactly the same problem. It appeared to start when I accepted the upgrade to Outlook 15.6. Have done a complete fresh install and still have the same issues.

Outlook 2013 works fine using VMWare.

Has anyone else linked the problem to the 15.6 update?

Yes! I'm having the exact same issues and now, with 15.6, I'm having a great deal of trouble downloading attachments automatically or otherwise.  I'm using Exchange.  

Microsoft at its worst...

HBR -- I found a solution to the sync errors:  go to your sent items and locate the record that's generating the error and delete it.  That worked for me.

After deleting Exchange account and set of of new, main problems are:

1. "Sync pending error" came back after a few hours after. Now have to restart Outlook to sent mail or make sure i have received recent mails. 
2. "Sync errors" continues - 4 logs per minute
3. Categories in Exchange calendar events disappeared after setting up new exchange account. Cannot set or edit categories any more.

Cannot continue to use a Outlook 15.x for Mac - for business!