sync failed. The requested parent profile (tcp) was not found. upgrading two boxes from 11.2 - 11.6

I just ran into the same issue. I was able to back trace and found that someone modified the parent profile on the secondary. It caused us to not be able to sync. I reverted the changes back to default and we still couldn't sync. I followed the example above and removed from the bigip.conf on the secondary and we were able to sync. I've never seen this before prior to this issue. We are running version 12.1.2 HF2 so the issue is still present.