Screen went black

My screen went black when i try to alt tab back into the game and i could do anything could not ctrl alt delete or anthing I had to wait until the game did a remake and force me into a priority lower que. I send a ticket and tell them is not even fair if this was a bug splat I could have just logged backed in and continued the game but this was not the case at all the game was just black I could still here sound and everything but that was it I could not do anything else. When i submit the ticket and asked them to remove the low que they send an automated response like come on man I have never complained about this but man this legit was not my fault and was the system fault alone. Plus on top of that i see in the sever status that it says the client is having issues with game crashing after you use highlights or replay in the league client and i just got done using that as well.

Here is proof because I just posted this right after i was done using the replay/highlight system in the client then soon as i start another game it goes black.

https://youtu.be/WnuuV59Z48w Their is the video of me using the replay highlight system

http://na.op.gg/summoner/userName=Roxas%20Rokusasu Here is my MMR of the game right after i played this one the screen is completely black.

http://na.op.gg/summoner/userName=Roxas%20Rokusasu You can see right were is says that in the sever status it caused problems. I do not deserve to have a low priority que if your client is the one at fault for this.