I've never had a problem ultimately resolving errors by the IRS. I'm sure that's not universally true, and it does take forever.

Respond immediately if you are notified of an issue. If you are actively working to resolve the issue that will help avoid getting in a situation where wages are garnished or liens issued.

Do everything in writing, sent by registered postal mail. Nothing they tell you over the phone is official.

Keep copies of everything related to the issue forever.