SMRuti, I had forgot to leave leading zeros in. I made that change and ran it and in fact I do get a different error. Here is what the bapi reports:
Material number 123456 in version already exists
I then changed from Storage View to MRP view and had the same error about it already existing.
I am a little curious in that anyways. Why would I want to modify the MRP view and not the Storage view which is what I am trying to modify?