There was an error attempting to send your changes to the exchange server.

iCal will no longer sync with my work Exchange calendar.

I have deleted and added the account several times, but that is not working.

I was getting messages about specific events not being synced with the server, but now I get the following message:

"Calendar can't refresh with the account "RPD Exchange"

There was an error attempting to send your changes to the exchange server"

Any ideas?

Thanks.