Internal gds software consistency check

When Firebird (or InterBase) instance cannot perform some operation without warranty that database consistency will be  not impacted, it raises an error (bugcheck) and interrupts current operation.
Such Firebird error text starts with mandatory prefix "internal gds software consistency check" (for recent Firebird versions it is "internal Firebird software consistency check"), and then an actual error text follows.
Often "internal software consistency" errors mean that Firebird database is corrupted (however, it is not a rule).

If you see such error in your firebird.log or as a error message in your application, follow these steps to make sure that your database is Ok: