Hi,
It seems this error can occur when your database is corrupted, or is restored without the post-restore SQL queries. I'd recommend running the following queries on the database giving you issues.
[embed:dc8ab71f-3b98-42d9-b0f6-e21e02a0f8e2:3635a448-6cb9-4b89-bc45-db20f362561b:type=text&text=--%20Query%201%20%28should%20succeed%29%0D%0Asp_change_users_login%20%27Update_One%27%2C%27innovator%27%2C%27innovator%27%0D%0AGO%0D%0Asp_change_users_login%20%27Update_One%27%2C%27innovator_regular%27%2C%27innovator_regular%27%0D%0AGO%0D%0A%0D%0A--%20Command%28s%29%20completed%20successfully.%0D%0A--%20Query%202%20%28should%20fail%29%0D%0Asp_grantdbaccess%20%27innovator%27%2C%27innovator%27%0D%0AGO%0D%0A%0D%0A--%20Msg%2015023%2C%20Level%2016%2C%20State%201%2C%20Line%201%0D%0A--%20User%2C%20group%2C%20or%20role%20%27innovator%27%20already%20exists%20in%20the%20current%20database.%0D%0A--%20Query%203%20%28should%20succeed%29%0D%0Asp_addrolemember%20%27db_owner%27%2C%27innovator%27%0D%0AGO%0D%0A%0D%0A--%20Command%28s%29%20completed%20successfully.]
