Unknown Error

When i was playing ranked earlier I was last pick with someone an I went adc so when i clicked on my marksman this screen pops up showing something loading then "Unknow Error" i see my my champion is picked and their was some delay because the timer was at 0 then nothing and at that point i couldn't click on anything so no changing to or masteries. Later into the game I couldn't move when everyone else was moving and my teammate said that to when he was being 1 v 5 when he could of escape but didn't, so can you please fix it. Thank you.