migration assistant locked out of computer

Hey there Alanabanna,

Thanks for reaching out to the Apple Support Communities. We understand you're unable to log into your Mac after transferring data using Migration Assistant, and we'd be happy to help.

To get started, have you had a chance to go through all the steps listed in the 'Related Article' that was shared along with this thread? Here that is again, just in case: If you forgot your Mac login password

If so, have you tried the steps in the additional resource provided at the bottom of that page? If not, take a look at these steps that can help further: If you can't reset your Mac login password - Apple Support

If still unable to log into your account after going through those steps, the next best option would be to reach out to Apple Support directly from this link here: Get Support - Apple

We hope that's able to help.

Have a great day.