Migrate to Jetpack compose error: Unbound symbols not allowed
I had the same problem. As a workaround, I replaced all Kotlin synthetic with ViewBinding. After I did it everything worked.
Apparently, this issue has been fixed and will be shipped to Kotlin:1.4.20 (Which is not released at the time)
Google issue tracker reference
[Update at 27 Nov]
Updating to 1.4.20 leads to another error [Ref]
I had a similar problem when I was migrating a template project. What fixed it for me was deleting some template code that accessed elements that were grabbed by findbyviewid.