Sage 300 Error: Causes, Fixes, and Practical Ways to Avoid Them If there's a thing that can ruin a productive day, it's the Sage 300 error popping up right when you have reports to run, invoices to be sent, or monthly entries closing. Sage 300 is powerful, however, like any software which handles databases, accounting and network communications mistakes do occur. And when they do, they can occur at the most uncomfortable timings. ...