I am trying to list an item and it keeps coming up with an error message "Please enter valid dimensions for your package"...help pls!

[jasmic0831]

I am trying to list an item to auction and it keeps coming up with an error message "Please enter valid dimensions for your package"...I had already listed my item and was thinking of just moving it to the auction category but it keeps coming up with this message.  I have gone into all of the required fields and can't see a field for this!!!! It is very frustrating...has anyone else had this problem because nothing I have done works.