@Denny Hi and welcome to the Forum 
Any reason to install SLES 12 SP3 since it’s EoL, unless your subscription is LTSS there will be no active repositories? SLE 12 SP5 is in general support…
@Denny Hi and welcome to the Forum 
Any reason to install SLES 12 SP3 since it’s EoL, unless your subscription is LTSS there will be no active repositories? SLE 12 SP5 is in general support…