iCal syncing with Outlook / Exchange

I believe I've fixed the issue. My calendar is now syncing with Outlook and Exchange.

The error message led me to the solution--- I found a support communities post from 2013 that resolved the issue (apparently).

I went to Users/myuser/Library/Calendars

Then deleted all of the Calendar Caches listed -- there were 3.

Restarted my Mac, then opened calendar. There was a message that Calendar was being rebuilt.

Now it works fine. Fingers crossed.

Still puzzled by the fact that the issue was there for 3 days before I saw the error message. But not arguing with success.

Update: I removed and reinstalled Outlook / exchange from my Mac.

iCal is now importing any entries on the Outlook Calendar. But items posted on iCal do not populate on Outlook.

Some progress.

I hope someone helps ...

Saw this error this morning when I logged in:

"Calendar encountered a critical error while saving to the database, and recent changes may be lost. More information may be available in the console."

Help please ....