- AliModule *mod = dynamic_cast<AliModule*>
- ((*gAlice->Modules())[gAlice->DetFromMate(gMC->VolId2Mate(i+1))]);
- (*fVolNames)[i]=new TNamed(gMC->VolName(i+1),mod->GetName());
+ Int_t mat = gMC->VolId2Mate(i+1);
+ if (mat > 0) {
+ AliModule *mod = dynamic_cast<AliModule*>
+ ((*gAlice->Modules())[mc->DetFromMate(gMC->VolId2Mate(i+1))]);
+ (*fVolNames)[i] = new TNamed(gMC->VolName(i+1),mod->GetName());
+ } else {
+ (*fVolNames)[i] = new TNamed(gMC->VolName(i+1), "Assembly");
+ }