Just a quick note on a scenario I ran into, and what I did to fix it:
- A user was running a stored procedure that created a table.
- Rather than having a table created in the "dbo" schema, it was creating a table with their user name as the schema, as in: DOMAIN\Username.TableName.
- The user was authorized via an AD group login.
- The user's individual user name was a disabled "User" in the database they were accessing.
- I specified the default schema to "dbo" in the AD account. I did this first and this alone did not fix the issue. The disabled user account's settings overrode this setting.
- Removed the objects in the database in their non-dbo schema.
- Removed schema (within the database, security, schema folder).
- Dropped the username
Perhaps changing the default schema on the disabled account would have also helped, but I didn't try that. There are only so many hours in a day.