What does Modicon Momentum M1E MSTR error code 5002 hex mean?

Issue
What does Modicon Momentum M1E MSTR error code 5002 hex mean?

Product
Modicon Momentum M1E
Modicon Concept / Modicon ProWorx - PLC Programming Software

Environment
Modbus Communication

Resolution
MSTR error code 5002 hex is an error message that could be generated by an MSTR block used in a M1E controller.
MSTR code 5002 hex = Bad Modbus Protocol.