I'm getting some strange lines on the ground if I try running this and Intangible. Not sure which mod is causing this, but disabling either fixes it.
Forge 11.15.1.1808

Sorry, I was thinking Intangable was a modpack for a second there...

The lines look too precise to be a glitch, but who knows... Are there any AgriCraft blocks within the loaded radius?

I rly want to figure out why that happens, this could make for a neat rendering effect for a potion effect/spell (unrelated). But I'd also like to know why this happens to fix it (related).

This is occurring on a newly generated world.
More pictures \o/