SAP Basis Tech Supports

Symptom
In the Business Rule Framework (BRF) maintenance, the runtime error UC_OBJECTS_NOT_CONVERTIBLE occurs (class CL_RULES_BASE_MNT_BRF; method IF_MAINTENANCE_BRF~INIT) when you try to create a BRF expression of the implementing class 0AO001.
Other terms
BRF, Business Rule Framework, UC_OBJECTS_NOT_CONVERTIBLE
Reason and Prerequisites
The incorrect maintenance class CL_RULES_MNT_BRF is assigned to the implementing class 0AO001. However, the correct maintenance class is the class CL_AND_OR_MNT_BRF.
Solution
Correct the BRF Customizing for the affected application classes, including the delivered application class FLIGHT:
Call transaction BRF for each application class in which the error occurs (also correct the application class FLIGHT).Change the implementing class 0AO001 (AND/OR Conditions of Boolean Expressions). Enter CL_AND_OR_MNT_BRF as the maintenance class.