Hi Anoop,
I am having the same curiosity/issue. The warning message SE 242 Runtime of entry must fall within runtime of Purchase Order is set as blank (not W or E) in the path IMG-MM-External Services Management-Define Attributes of System Messages. I think this is a system message that is hidden somewhere or cannot be configured. I guess we need to change the System message Catergory of SE 182 Entry must be within validity period of purchase order (& - &) to either W or E. Is that correct? Hope you could clarify. Thank you.
Regards,
Chester