@Osprey00 There are like a bazillion different versions of 6.1 gcam under this link. Can You specify witch version You used?
Sorry. I did mention a version somewhere, but it must've been a different post. Just download the latest (top-most) one. If, for whatever reason, that doesn't work, try the latest one that starts with "MGC." I think that they all work, just with tiny differences. I don't recall if I prefer any one over another.