Hi,
The price difference generated in the screen shot above seems to be morethan available PUP in the material master. When you run CKMLCP, system will try to revaluate your inventory by considering the price difference, hence system given this error message.
You need to revisit the differences posted in the CKM3N are correct or you need to foreclose the period for this material manually using CKMLHELP
Bhaskar