"Your computer is low on memory"

Hi, I've been playing league for a long time with my Mac and recently after the new update, I haven't been able to play cause I got an error message saying that my memory is low and that I need to free up more memory, but here's the thing, I have 55.68gb of free memory, and I tried to clean my RAM as well and I still keep getting the same message, over and over again. I need help cause I feel like this is a bug at the point, I even tried to uninstall and reinstall it again, and nothing. It's annoying when every time Leauge comes out with a new update, it takes up more memory. It's even more frustrating that I can't get rid of the pop-up window from when I play, cause that's the only time it ever pops up. So at this point, I can't even play any games, cause the pop-up warning screen is in the way. If anyone can help, that would be great.