Thoughts?
Message: Ghost was able to start, but errored during boot with: Migration lock was never released or currently a migration is running.
Help: If you are sure no migration is running, check your data and if your database is in a broken state, you could run knex-migrator rollback.
I got the same error after upgrading from 4.3.3 to 4.13 
In my case during the upgrade something was missing (perhaps npm updates, but I also upgraded Ubuntu, worst choice ever)
After upgrading Ghost, restarting it gives this problem.
If I reboot the server ghost status is running but trying to access the website gives a nginx error.
Any way to rollback to the 4.3.3 version maybe?