An externally defined function returned null. Group name = aa....aa, class name = bb....bb, method name = cc....cc

aa....aa: Group name
bb....bb: Class name
cc....cc: Method name

Description:

The method that implements the externally defined function returned null.

System processing:

Blocks the query group.

Action to take:

Revise the processing of the method that implements the externally defined function. If you fix the class file, delete the query group, and then re-register it.