Message no. MPN113-Entry with similar validity period already exists for MPN

Hi Gurus,

I am getting below error message while maintaining MP01 for IM material. If I add same MPN material multiple time with same data, it must restrict and give error message but it is giving information message even though i set it as E.

Message no. MPN113-Entry with similar validity period already exists for MPN

Any ideas?

Thanks,

Kumar