Garry's Mod:Stuck on blue loading screen.

When the blue load screen popped out.it just gonna stay there forever.I’ve no idea what to do.It’s bloody stuck.yesterday is the only first and last time I get to see the g-mod main menu screen,and its very very slow,not responding for a few seconds,stuck on loading world.

I say,why it must be stuck on the blue loading screen

Try to verify the integrity of game cache to do that right click on gmod in the library goto properties goto local files then click on verify integrity of game cache if that doesn’t work I believe your pc is too old and you need a new one Hope this Helped if not tell me I will try to help more.