Error upgrading from SLES 12 SP5 to SLES 15

Im trying to upgrade a VM server from sles 12 SP5 to 15 through a boot from a virtual CD ( [SLE-15-SP5-Full-x86_64-GM-Media1.iso] But im getting this error after boot, and initial load:
Selection_108

Error
Internal error: private constant Y2Package ProductUpgrade MAPPING refrenced.