Versions used:

• BetterQuesting 2.3.215
• RF Expansion 2.3.24
• Standard Expansion 2.3.124
• Better Questing Triggerer 0.8

First crash, with only those four mods (Was checking out the mod for the first time; Made a new quest line, added a new quest, added a single new task of type scoreboard, then clicked the "Advanced" button)

Second crash, after adding ITank, although probably has nothing to do (Edited the task mentioned above, and changed the "name" to a valid scoreboard objective, changed number from 1 to 4, then pressed Done)

My bad, this should go over at StandardQuestingPack's tracker. Sorry!