Application :: contextError - Get last context error
Usually, context error will not be reset and may be checked until the next error is set.
Return value:  Error number ( int32  )
The internal error number identifies an error within an error class. Errors might be documented in the error class within the resource database.
Implementation details
int32 
Application  :: contextError (  )
The function returns the last error registered from business rules (context classes).

