Suse Linux Upgrade Failure from SLES12 to SLES15

I am trying to do offline upgrade for Suse Linux Version SLES12 SP05 to SLES15 SP03 (Vmware environment). I booted the system from ISO image of SLES15 SP03. while clicking next -->next, I reached to window select for update… “Partition or system to upgrade” where it is showing root file system xfs and X86-64.when i click next, wait sign comes for certain time and then error window appears with OK button only “internal error…execution expired”. when i am clicking OK its just go back to the old window as mentioned above. unable to find any help. please help me to resolve this issue.

@Adeel_Siddiqui Hi and welcome to the Forum :smile:
So your following this guide for the offline upgrade

Does the system have a current registration and internet access as you may need to add media_upgrade=1