CPF9999 is a gobal escape message used bu IBM.
There are parameters passed to it so that when you get it you will have enough information to determine your problem.
CPF9999 is the general ‘function check’ message. A function check condition is similar in concept to ‘machine check’ except it refers to software faults that have no error correction procedure rather than hardware error correction.
Very simplified, it means that the program ran into an error and did nothing about it. Whoever wrote the program needs to fix it. The CPF9999 message will include the error condition that was ignored and needs to be fixed.