Reverse Branching sometimes crashes (0.6.0)

[dreamsyntax]

Need to collect sample seeds. Reported by Jesus-PK

[dreamsyntax]

You can quickly reproduce this with a ban list +15 and reverse branching. - Jesus_PK

The program itself crashes
on line 1250
while (orphans.Count < exitcnt - stages[stagepool.Peek()].CountExits())
with
System.InvalidOperationException: 'Stack empty.'