Try to open toolbox after update Immersive Engineering 0.12 - 87 and crashes everytime. Works fine with previous one. Error says be related with mouse tweaks mod (not changed).
crash-2018-12-10_19.13.11-client.txt

I crash every time I try to right click on the toolbox or revolver so far. It's not all GUIs because the workbench is fine. Oddly, the crash logs all seem to have me in an MP server when I'm playing SP client...
https://paste.dimdev.org/kunevuhocu.mccrash

Same on server : https://pastebin.com/CBt17wAR

Same one all guis on my modpack "Dimension Zero" running on the recomended forge version14.23.5.2768.
https://pastebin.com/ZsJpQYdi

I had this same issue when trying to open a revolver speedloader.
https://pastebin.com/mraTn2Nn

Then I tried again the Toolbox, same result
https://pastebin.com/SLVMZRwF

Is there a fix for this? I have the same problem.

@DragonmasterDJ Update to 0.12-88 to fix it.
For future reference, "closed this in " means that a code change was made to fix an issue, and if you click on it you can see if it's been tagged in a version release yet.