That is serious. You can suppress the domain violation by only taking records that match your sets by replacing $loadDC by $load. This is extremely dangerous, since you have no clue of what you leave behind, so the results of the model are very questionable. If you have to use a complex model like IFPRI's CGE model you need to invest in learning the basics. Depending on your set up and environment it might be advantageous to seek external help, e.g. your professor, or attending a GAMS class (e.g. Bruce McCarl's on-line GAMS course in a few weeks:
https://www.gams.com/courses/) or hiring consultant (check with
support@gams.com for options).
-Michael