Here you go.
It is unfortunate that this happens, but it only present when your mod is present.
I have tested it before without your mod, and I could use minetweaker on logistic pipes.
As a suggestion provide us with alternative function to get logistic pipes items as function for example.
This seriously bugs me, as I will be missing entire tech step process in modpack without it. And your mod is also fairly necessary to get proper crafting recipes for many mods.
I have isolated LP to separate script, which I attached, primary script doesn't have any issues, but I can attach it too if necessary.
I used latest BC 6.4 LP and BC, as I originally though that LP just needed an update, as I usually don't update mods unless some important fixes came, and since most BC features disabled anyway and LP didn't have any visible problems as I plaid.
So in short, this fails with old LP for BC 6.2 and BC 6.4.
I believe your mod somehow causing class find function to miss fire, though can you perform manual check on it? To see if find class function performs properly? That would tell us if function fails, or MT fails at using it, if your mod is present.
	
	
		java.lang.ClassLoader.findClass()
	
	 
And I wonder if error persist on dedicated server, I havent tested my self yet.
Good luck at figuring it out, I saw Github issues post, but it didn't resolve anything as bug wasn't looked in closely there.