I had this problem with the Ubuntu 23.10 package. The suggestion to
remove the obsolete /usr/share/emacs/site-lisp/elpa/ess-18.10.2/
directory resolved it.
- Bug#1052458: elpa-ess: ESS mode in Emacs fails ... Hugh Pumphrey
- Processed: Re: Bug#1052458: elpa-ess: ESS ... Debian Bug Tracking System
- Bug#1052458: elpa-ess: ESS mode in Emacs f... Sébastien Villemot
- Re: Bug#1052458: elpa-ess: ESS mode in... Chris Sims
- Bug#1052458: marked as done (elpa-ess: ESS... Debian Bug Tracking System
