Office 365 subscription not activated

Hello,

Since yesterday that I'm having the following issues with outlook for mac:

1. When opened, it shows only the outlook menu bar, on the top;

2. I'm on a microsoft exchange server. Deleting the account and creating it again gives me the following error, "Your account can't sync because your office 365 hasn't been activated" . (Until yesterday I was ok);

3. Already re-installed office 365 and outlook for mac but nothing changed;

4. With the previous office 365 outlook version everything is ok but going back to that version will make me loose all emails stored on my PC with outlook for mac and that information is critical for me. 

I need for guidance on how to fix this.

Pedro.