League keeps closing during game??? pls help

So whenever I'm in game suddenly league closes to my desktop where i see my music (because I have soundcloud playing in the background) and on the bottom it shows both the new and old league client? Like just the icons next to each other. Once I click the icon it leads me back to my game where I'm in the same position I was when it switched. At first it didnt really matter but now it's happening during team fights so I'm not able to help and I have to escape getting killed. What's happening? Should I unistall league then reinstall it? Or could it be something with both the old client and new client appearing?