When I use the chisel to turn a stack of blocks into another, the output is a single block. For example, here I am trying to chisel 5 blocks of dirt, and only one block is returned: https://gfycat.com/BadMeanFairyfly

I was experiencing this as well, but only in a mod pack. I cannot reproduce it with only chisel. Can you test and see if it behaves the same for you?

Yeah, the issue is happening on HermitCraft 1.1.0 using the version 1.9.4-0.0.6.51 of Chisel. I'll try removing all the other mods in the pack.

I tried disabling every mod of that pack excepted for chisel, and the bug still happens. Here's a screenshot of the mod list ingame: http://i.imgur.com/Q4F2Zau.png

MCMultiPart is not part of forge. Please try with it removed, although I doubt it is the cause.

Then the launcher is broken. it's a normal mod like any other. Go remove it manually from the mods folder.

I'm using the FTB launcher, it does not allow me to remove that mod as far as I know... This is what the mod list looks like in the launcher: http://i.imgur.com/1SZWNUU.png

Alright, it wouldn't disable because it's located in a sub-folder of the mods folder. After deleting it, the problem still occurs. Here's the current in-game mod list just to be sure: http://i.imgur.com/8dbzSly.png

@samuellapointe please file a bug for the FTB Launcher disabling issues https://github.com/Slowpoke101/FTBLaunch/issues

@samuellapointe Could you try this build to see if the problem persists?

http://ci.tterrag.com/job/Chisel/branch/1.10%252Fdev/2/artifact/build/libs/Chisel_DEV-MC1.10.2-0.0.6.2.jar

Unfortunately, it still happens with that version, even with all the other mods disabled.

Here's something someone on reddit sent me:

if you are on single player / have access to config files - change it so the chisel can take damage (in the chisel config) then you can so stacks again

This fixed my problems.

That's strange, but I think I might know why it happens. I'll look into it soon.

Fixed via eeb0cbd