Seaquel
SQL Server error code

SQL Server error 6534

SQL Server raises error 6534 at severity 16, which marks a problem with the query or data that you can correct.

AppDomain %.*ls was unloaded by escalation policy to ensure the consistency of your application. Application failed to release a managed lock. %.*ls
Msg6534
Severity16
Group6000–6999

Source: Database Engine events and errors