Big Box turn black screen ...

hi there ,

I recently notice when I go to big box and move the platform wheel some time the screen turn black I could herd the sound of music but all black and some time the video game play also turn black , also I install the new update and when I went to theme manager try to install theme its freeze and shutdown ? any idea to solve these issues ?

my pc spe intel i-8400 ram 8 gb hhd 10 TB number of game around 12000 games :)