By running the following command:
select * from DATABASECHANGELOGLOCK;
You should be able to check the lockedby
column to see who locked the table. Generally, the lock will be from the local machine.
Assuming this is the case (and no other machine has a lock on the database), this should resolve the issue:
Execute the following SQL query against the database:
update DATABASECHANGELOGLOCK
set locked=0, lockgranted=null, lockedby=null
where id=1
Please let us know if you encounter any issues.