@UEGT2541J I havent seen this, so I would be interested to know: did you run a package upgrade? did you edit any of the elisp files in the clojure layer? did you add anything to .spacemacs, especially new keybinding definitions? did you add a new layer? did you add a specific package?

Have you just tried restarting Emacs and seeing if you still get the same error? Sorry, these are all fairly common sense things I am suggesting, as there is not very much context to go on.

If a reboot does not fix it, try delete all the clojure layer packages from your .emacs.d/elpa directory and restart emacs

What I did eventually was to remove macs/spacemacs totally, then I copied a working copy of .emacs.d and .spacemacs from my other computer and it worked out.

I must have been a config issue somewhere - I tried reinstalling etc. but nothing worked. I have no explanation for it. But sorted

Tricky problem to solve. You made a good choice on how to fix it.