Never seen this before. And it's weird. Casting light spells on myself doesn't actually result in adding light to my character. Any idea on what could cause this?

Try loading all your active mods at once in TES4Edit and see which ones are changing the LGHT (or was it LIGH?) magic effect. If there's is nothing odd to see there, try looking at the actual light the effect uses (should be somewhere in the data fields for the magic effect) and see if any mod is changing it somehow.

I re-posted in the LAME thread. Somehow, editing LAME's custom fire enchantment shader prevents light spells from working. Took me forever to realize the cause, but without a doubt, that's what caused it. How? I have no clue. Very strange issue.

Thanks btw, I didn't know of TES4Edit's ability to search for specific changes like that. That's awesome.