E2158 %s unit out of date or corrupted - missing '%s' (Object Pascal)
The compiler is looking for a special function which resides in System.dcu but could not find it. Your System unit is either corrupted or obsolete.
Make sure there are no conflicts in your library search path which can point to another System.dcu. Try reinstalling System.dcu. If neither of these solutions work, contact Embarcadero Developer Support.