Details:
Inventory swap is occurring within GUIs with Quark Installed, and is not listening to canTakeStack on the slot, so is causing dupe bugs on locked slots such as the Canvas bags in Blue Power Qmunity/BluePower#532. I can probably workaround this on my side for now.

Problem Feature:
FToSwitchItems

Log File:
latest.log

Mod Versions
AutoRegLib-1.4-35.jar
Quark-r2.0-204.jar

How would you like me to handle the GUI part of this issue, MoreThanHidden?

That should fix the issue by the looks of it.

Thanks.