You can "brick" a skill gem. It seems i have found a way at least...

I was playing around with making a shock on cast charge with both weapon sets but only trigger with one... Turn out...That can break things...

This lightning Conduit gem no longer shows up as a selectable spell.
It does not even register when you socket it into a meta gem.
I tried verifying the game file via steam, but it was still "off"...

Sometimes it shows text from player stats, other times it shows text from meta gems.
All of it incomplete gibberish
Well look at it.