GMod crashes: Current server version -32704

After screwing around in single-player, well more of me spawning “The Internet” floppy disc and putting them into a toilet I found off the internet, yes, I get THAT bored. Then I decided to make a tower of them and watch them fall using the stacker tool. So I put 100, or so I thought, in the amount of prop I want stacked and clicked on the floppy and then GMod stop to hesitate intill it booted me from the game and back to the start screen.
I checked the console to see what caused GMod to crash and I found this.

Server returned version -32704, expected 21.

Server downgraded itself…how funny.