Caller of lock manager is incorrectly trying to unlock an unlocked object. spid=%d locktype=%d dbid=%d lockid=%Id.
This error occurs when SQL Server is engaged in some activity other than normal post-processing clean-up and it finds that a particular page it is attempting to unlock is already unlocked. The underlying cause for this error may be related to structural problems within the affected database. SQL Server manages the acquisition and release of pages to maintain concurrency control in the multiuser environment. This mechanism is maintained through the use of various internal lock structures that identify the page and the type of lock present. Locks are acquired for processing of affected pages and released when the processing is completed.
Run DBCC CHECKDB and DBCC NEWALLOC against the database in which the object belongs. If DBCC reports no errors, attempt to re-establish the connection and execute the command. If the problem persists, or if there are structural problems reported, contact your primary support provider.