My maps keep randomly leaking help!!

one day i will be happily playing gmod. then… THE WHOLE MAP LEAKS EVERYTHING! ALL OF THEM HELP ME!!! IT HAPPEND TWICE IVE REBUILT CACHE TWICE!!! HELP!!!

Uhm, explanation please?

u know when u usually see leaks in random areas of maps everything goes all bright well that happens to me … all of my maps do that all over the only way ive been fixing is rebuilding cache and its getting annoying how can i prevent this from happening

What?