Which class 101 do you have, the northern trans-pennine one (2 car) or the tees valley line one (3 car) or both. If you only have one of those types then it is because the livery you got is for the 101 on the other route. If you have both then it's a problem
do you also have the ntp or tvl one? some of the liveries on cc are for those 101s not specifically the gwe one