Seaquel
SQL Server error code

SQL Server error 3993

SQL Server raises error 3993 at severity 16, which marks a problem with the query or data that you can correct.

The user transaction that has been started in user defined routine, trigger or aggregate "%.*ls" is not ended upon exiting from it. This is not allowed and the transaction will be rolled back. Change application logic to enforce strict transaction nesting.
Msg3993
Severity16
Group3000–3999

Source: Database Engine events and errors