I'm a bit confused, but I'll try to answer as best I can...
There is a bug in 11.2.b2 which means old band structures from 10.8 cannot be opened. This is fixed in 11.2.r1 which will be available shortly (today, maybe).
As for the copy thing, I don't understand the issue, but generally, the atoms may end up outside the cell, in which case you have to extend the unit cell manually. It might be better to repeat, rather than copy.
Graphene has no band gap, so it will be hard for the script to find one. The script is designed for materials with a real band gap (although h-BN has, so it should work there).