If deleting every other addon that contains blood "(That can be in certain "Improved Decals" mod) doesn't fix it, I don't know. That problem is certainly caused by the fact that the texture is not resized because you have another conflicting addon.

yes man

There is a bit of a bug with the placement of textures with mine such as the off ramp at the start of Dark Carnival.

There is also an error with the Common Infected bloomapping with gore impact. It just turns hat whole side of the ragdoll very dark red.

Maybe I can help ya, okay, so if you said that you unsubbed from other Blood mods, and you still don't have the 4K mod working, then do this stuff:

Step 1: go into your L4D2 Directory, by closing L4D2, then right clicking it on your 'Games' on Steam, pretty much going to Left 4 Dead's Properties, but Steam style, then click 'Local Files' and look for 'Browse Local Files' and if it isn't there, make sure you're not on any skins, some skins MIGHT remove it, you can still try with your skin cause I don't see why it would remove that, anyways, now that you're in your Directory,

Step 2:find a folder called 'left4dead2' then go to 'Addons' then go to 'Workshop' then your should see some or many files, depending on how many mods you've subbed to - anyways, you should see loads of pictures in there, or just some, now this is where its confusing,

Step 3 [Confusing]: you have to click on the pictures, not more than 1, just find a blood mod, [not the 4k one] and then once you've found a picture for a Blood mod you've unsubbed to, you should see a .vpk **BELOW** the picture with the blood mod, and you want to either move it [recommended], just in-case it doesn't fix it, or just delete if you dont care about the mod
DISCLAIMER: DELETE/MOVE THE PICTURE AND THE .VPK FOR SAFE PURPOSES, and then try again, you might have more blood mods, so if it doesnt work, try it again.
Hope this helped! :3

P.S If you don't think you should do this then don't, like if you're not used to modding or messing with game files, but the reason why you have to do this for the 4K mod to work is because sometimes Unsubbing doesn't actually delete the .vpk put in the Workshop folder for the mods. So yeah, just wanted to clear any confusion.

boom shakalacka