I just made other report, but I think this is a different problem, so I decide to made in 2 different Issue, but for informations, you can see #3150

So, The probleme I found here, is using a Glistering Melon, but possibly it appen with other things I didn't try all potions or all recipes from the mixer ;)... When I add to the Awkward potion fluid, Glistering Melon, the Melon never been consume, so I can make unlimited Healing potion with only one melon and take back the melon after all that, with a Shift-Click :)... So, free Healing Potion, that's nice, but, I don't think this is Intended Feature ;)

I don't think this issues came from my Potions Mixer Recipes scripts I made, but, you can see all informations for that in my other issue...

Here 2 capture, both with the same melon :

Crashlog:

This is not a crash, but an issue with the mod I think, so, I'm not sure if you need logs files, but if needed, I will provide-it.

Versions & Modlist

Immersive Engineering: 0.12-84
Immersive Petroleum: 1.1.9
Immersive Tech: 1.3.10

CraftTweaker2: 4.1.9
Forge: 14.23.4.2705
Minecraft: 1.12.2

Java : 1.8.0_171 (64 bits)

FireZtoneZ

Thanks for the report, I found this a few days ago and fixed it in a93f4c7.

Ok nice!