Seaquel
SQL Server error code

SQL Server error 8936

SQL Server raises error 8936 at severity 16, which marks a problem with the query or data that you can correct.

Table error: Object ID %d, index ID %d, partition ID %I64d, alloc unit ID %I64d (type %.*ls). B-tree chain linkage mismatch. %S_PGID->next = %S_PGID, but %S_PGID->Prev = %S_PGID.
Msg8936
Severity16
Group8000–8999

Source: Database Engine events and errors