Downloading Replays

It may be because I have a lot of saved clips but now the plays I record aren't downloading properly. Sometimes the sound stops mid-replay or doesn't play at all and rarely I get some high-pitched screeching noises, kind of like the sound you get when you drag your nails down a chalkboard. There are also a few videos that are problem-specific towards champions like Pyke. Whenever he uses his W, the sound is deafening but all other noises are normal.