Industrial Foregoing Version: 1.16.5-3.2.14.7-16

Titanium Version: 1.16.5-3.2.8.7-22

Edit 1: after thoroughly testing with fresh install of forge 1.16.5, I can confirm the issue isn't apparent.
Edit 2: Possible conflict or compatibility issue with 1.16.5 Quark-r2.4-322 and Quark-r2.4-321 Quark mod -- quark github

Crashlog If Applicable (Upload to pastebin/gist): https://pastebin.com/dAdPY7ax

• Place a dispenser
• Place a button on dispenser
• Place an Industrial Foregoing conveyor inside dispenser
• Use button
• Server or client will crash afterwards.

Issue been discovered by @circee within Enigmatica6

After I personally tested few mods, the only mod that having incompatibility issue with industrial forge within E6(Enigmatica6) is Quark.