Issue: Cannot connect to exchange on LRS.
Error Message: We can't connect to exchange. You might not have the latest room calendar info.
Problem Statement: If you see this error message that means your exchange web services are not syncing and calendar is not updated.
It might your exchange is unavailable.
Resolution is very simple make sure your exchange server is available and Exchange web services are working.
Second you can just log off or restart LRS Room account.