The log reader agent or the CDC scan job executes the sp_replcmds stored procedure to return commands marked for replication. In Microsoft SQL Server, if the stored procedure is canceled during execution, a failed assertion that resembles the following may be logged in the SQL Server error log:
Error: 17066, Severity: 16, State: 1.
SQL Server Assertion: File:< replicat.cpp>, lineNumber Failed Assertion = 'db_mem'. This error may be timing-related. If the error persists after rerunning the statement, use DBCC CHECKDB to check the database for structural integrity, or restart the server to ensure in-memory data structures are not corrupted.
Additionally, multiple access violation dump files are created after the failed assertion dump.
This issue is fixed in the following cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.