Thanks for your help, but i managed it fix it! Turns out i installed <kuid2:661281:85115:3> that was faulty, which replaced <kuid2:661281:85115:2> and made it obsolete. I just deleted the faulty asset and it is all good!
So basically I downloaded a route, which for some reason included PBR Grass 8. But I'm pretty sure the file was faulty. The problem is now in any instance of that texture, it is faulty. I've tried reverting to original, which just does nothing, and I have tried doing a DB repair, which also...