I can't find the post with the explanation. Odd.
I was having some problem with my Blockland install. For some reason, the game wouldn't start, being 'stuck' on the console screen.
I attempted to re-install the game to see if that fixed it. I chose to install it in the same folder to overwrite corrupted files.
I forgot to check 'Backup Old Add-Ons'. The installer wiped every file in my Add-Ons folder, including an early version of Bots where they could move and jump.
To try and get them back, I attempted to use a hacky 'Un-deleter' program. This found and restored nearly everything... except the cs files. Which meant I could get everything back (all the Add-Ons I had), but for some reason the Bots files were just permenantly deleted.
I haven't worked on it since that.