In "Unit_Control_0.2.0\data\util\tf_util.lua" at lines 131 and 139 there are file paths with "tf_util" in them. I believe they are supposed to only be "util". Making this change resolved a conflict with Rampant v0.18.4 on Factorio v0.18.8.
Thanks for all your hard work!

What error does it give with rampant?

Taken from Factorio log:
Mods to disable:Failed to load mods: File not found: __Unit_Control__/data/tf_util/empty-sprite.png
Mods to be disabled:
• Rampant

It is possible other mods are involved (I'm running quite a few) but this is what the error listed and led me to the lines I mentioned. Making the change prevents the error.

Quick update: The changes mentioned resolved the error on startup. I haven't done any play testing. I'm having too much fun in Satisfactory Update 3 right now. ;)

I'm getting the same error...

I added the following line to my mod which made it show up:
local hit_effects = require ("base.prototypes.entity.demo-hit-effects")

Fixed now

Thank you!