What I expected to happen was...:
Tried to simply change the resource pack from one made by that tool to the default one.
What actually happened was...:
Minecraft crashed D:
There is the crash log attached.
MC-17995
Crash when changing texture/resource pack
Resolved
Duplicate
0
Duplicate of MC-17831, please use the search function to see if your bug has already been submitted. Currently over 57% of tickets are being closed as duplicate.