Bug with Lux's e (lucent singularity)

Recently I played a game as lux mid, about 14-15 minutes into the game I threw out my E to harass the enemy zed, my e proceeded to disappear into thin air doing nothing, but not allowing me to detonate it. This left the ability permanently in it's second cast (detonate) but i couldn't actually detonate it as it didn't appear to be on the map. I was not able to cast the spell the rest of the game, and lost the game because I lost my most reliable source of damage.

Note: I tried everything, waiting, zhonyas, exiting and re-entering the game, dieing, I could not get the spell to work again.