You are out of storage space error.

I was playing in my creative world which I have had for over 2 years now and went to a house I built. The house was glitching with blocks like the door not responding but I could fly through then and blocks places down we're none existent with just the outline of the block. I went upstairs in the house and then it froze for about 4 minutes and all the mobs and animals sounds came on and then the world threw me out saying my storage space is full. I've gotten into the world a total of 2 times since and it kicks me out after 2 seconds. I also can't even copy my world.

I'm very confused what storage space is talking about.