Game Version: 1.1.0
Evoker with expanded mind perk.
When switching evoker to another specialization and back again, the spell gems/slots granted by the perk are not saved. This causes the spell gems to need to be re-equipped again when switching back to Evoker. Six monsters multiplied by five spells, results in having to equip 30 spell gems back onto your monsters. This is quite a nasty surprise for anyone switching just to see what another specialization does.
Saving the gems as part of an item set helps alleviate this by only having to do 6 re-equips, but its not something anybody would know until after disaster strikes.