Value determination using callback failed for condition field &2

What causes this issue?

Value determination for field &V2& of ILM object &V1& failed in the
following callback method:
Class:,,&V3&
Method:,,&V4&

System Response

Rule determination for the current object instance is terminated.

How to fix this error?

Correct the implementation of the callback method.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.