Crash upgrading Adherent's Staff

[temp]

I have an adherent's staff which I upgraded from a disciple staff.

Here is the description:
An adherent's staff, decorated with runic symbols.
+10% to Damage from lightning

Type: Weapon
Race: Humans
Cost: 6000

- Disciple Staff
- Adherent's Staff
- Archmage's Staff

However, every time I try to upgrade it by battling the gremlins in the archmage's staff, the program crashes. It happened 3 times already.