Racket upgrade (8.17) with Emacs racket-mode - the curse of racket-mode-start-faster

Install Racket 8.17 and now emacs won't start my Racket REPL. I did migrate everything from my previous version and did not touch the emacs config.

Suggestions?

racket-mode-start-faster compiles the Racket files used by racket-mode. It needs to be re-run when you upgrade Racket.