LoL client freeze please help ASAP

i am using the new client, i have played games inbetween this happening, but i open league fine get into a game okay timer ends game opens i get the blue and red skin/card outlines but no champions load and the client freezes, i cant close it i cant open task manager i cant alt tab i cant do anything i have to hold the button on my computer and shut it off, (btw is this actually bad. i feel like someone told me it was so i hate doing it but i have a need to play league)