All pages after level 1 showing 404 after WordPress migration plugin – how to fix?

Go to Dashboard > Settings > Permalink Settings.
However it’s set, change it to something else, one of the other formats. I had an issue moving, same symptom as you described, and this fixed it.

You can also see this help guide on Go Daddy for help with this issue. (this edit added by another user. NP, but details almost identical. /JTP)