Seaquel
SQL Server error code

SQL Server error 6205

SQL Server raises error 6205 at severity 16, which marks a problem with the query or data that you can correct.

%s ASSEMBLY failed because assembly '%.*ls' was compiled with /UNSAFE option, but the assembly was not registered with the required PERMISSION_SET = UNSAFE option.
Msg6205
Severity16
Group6000–6999

Source: Database Engine events and errors