Diagnosis
Operators 'EX' and 'NX' check for the existence (or non-existence) ofan object, for which a valid object reference must be available in thecontainer or must be accessible via a container expression.

Procedure
Please ensure that the operand entered as expression 1 has an objectvalue. The object references are highlighted by a special symbol in theexpression tree.
The object reference to be checked must be entered as expression 1 (onthe left side).
You must not enter a multi-line container element, also if the linetype is an object reference.
Operators 'EX' and 'NX' only use one operand. Expression 2 is deletedwhen operators 'EX' or 'NX' are inserted.