Symptoms
Assume that you create or configure an Always On availability group for an availability database by using the ALTER AVAILABILITY GROUP ADD DATABASE or CREATE AVAILABILITY GROUP FOR DATABASE statement in Microsoft SQL Server 2012 and SQL Server 2016. When the availability database is accidentally dropped, an access violation (AV) may occur. Sometimes, SQL Server may even crash.
Cause
This issue occurs because the ALTER AVAILABILITY GROUP ADD DATABASE statement and the CREATE AVAILABILITY GROUP FOR DATABASE statement don't acquire database locks when you create or configure the Always On availability group for the availability database. Therefore, the database might be deleted accidentally.
Resolution
Service pack information for SQL Server 2012
This issue is fixed in the following service pack for SQL Server:
Service Pack 4 for SQL Server 2012
For more information about how to obtain the latest service pack, see How to obtain the latest service pack for SQL Server 2012
About Service packs for SQL Server
Service packs are cumulative. Each new service pack contains all the fixes that are in previous service packs, together with any new fixes. Our recommendation is to apply the latest service pack and the latest cumulative update for that service pack. You do not have to install a previous service pack before you install the latest service pack. Use Table 1 in the following article for finding more information about the latest service pack and latest cumulative update.
How to determine the version, edition and update level of SQL Server and its components
Service pack information for SQL Server 2016
This update is fixed in the following service pack for SQL Server:
Service packs are cumulative. Each new service pack contains all the fixes that are in previous service packs, together with any new fixes. Our recommendation is to apply the latest service pack and the latest cumulative update for that service pack. You do not have to install a previous service pack before you install the latest service pack. Use Table 1 in the following article for finding more information about the latest service pack and latest cumulative update.
How to determine the version, edition and update level of SQL Server and its components
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminologythat Microsoft uses to describe software updates.
