Failed to set one of the program properties

Problem saving one of the program properties. The error message indicates one of these conditions:

The name is invalid.

Entered an invalid name or a name that does not follow the IEC-61131 naming standards. Reenter the name using the format defined by the standard.

The description is invalid.

Entered a description with invalid characters. Reenter a valid description via the program properties.

The main routine is invalid.

The routine does not exist or is already associated as the Fault Routine.

The fault routine is invalid.

The routine does not exist or is already associated as the Main Routine.