When following a suggestion for solving another problem, I'm doing M-x package-list-packages. However, that gives me the error message Invalid version list `(4 5 -4 414)'. What does this mean, and what can I do about it?

If I do M-x toggle-debug-on-error before, doing M-x package-list-packages additionally gives me the backtrace

Debugger entered--Lisp error: (error "Invalid version list `(4 5 -4 414)'")
  signal(error ("Invalid version list `(4 5 -4 414)'"))
  error("Invalid version list `%s'" (4 5 -4 414))
  package-version-join((4 5 -4 414))
  package-menu--print-info(((merlin 4 5 -4 414) "available" "Mode for Merlin, an assistant for OCaml"))
  mapcar(package-menu--print-info (((0blayout 1 0 2) "available" "Layout grouping with ease") ((2bit 1 0) "available" "Library for reading data from 2bit files") ((a 1 0 0) "available" "Associative data structure functions") ((aa-edit-mode 0 0 2) "available" "Major mode for editing AA(S_JIS Art) and .mlt file") ((aas 1 1) "available" "Snippet expansions mid-typing") ((abc-mode 20140225 944) "available" "Major mode for editing abc music files") ((abridge-diff 0 1) "available" "No description available.") ((abs-mode 1 5) "available" "Major mode for the modeling language Abs") ((abyss-theme 0 7) "available" "A dark theme with contrasting colours.") ((ac-alchemist 0 1) "available" "auto-complete source for alchemist") ((ac-capf 0 1) "available" "auto-complete source with completion-at-point") ((ac-cider 0 2 3) "available" "Clojure auto-complete sources using CIDER") ((ac-clang 2 1 3) "available" "Auto Completion source by libclang for GNU Emacs") ((ac-dcd 0 6) "available" "Auto Completion source for dcd for GNU Emacs") ((ac-emacs-eclim 0 4) "available" "auto-complete source for eclim") ((ac-emoji 0 2) "available" "auto-complete source of Emoji") ((ac-etags 0 6) "available" "etags/ctags completion source for auto-complete") ((ac-geiser 0 1) "available" "Auto-complete backend for geiser") ((ac-haskell-process 0 7) "available" "Haskell auto-complete source which uses the current haskell process") ((ac-helm 2 1) "available" "Auto Complete with Helm") ((ac-html 0 31) "available" "auto complete source for html tags and attributes") ((ac-html-bootstrap 0 9 3) "available" "auto complete bootstrap3/fontawesome classes for `ac-html' and `company-web'") ((ac-html-csswatcher 0 1 7) "available" "css/less class/id completion with `ac-html' or `company-web'") ((ac-inf-ruby 0 4) "available" "Enable auto-complete in inf-ruby sessions") ((ac-ispell 0 7) "available" "ispell completion source for auto-complete") ((ac-mozc 0 0 4) "available" "auto-complete sources for Japanese input using Mozc") ((ac-octave 0 7) "available" "An auto-complete source for Octave") ((ac-php 2 4 2) "available" "Auto Completion source for PHP.") ((ac-php-core 2 4 2) "available" "The core library of the ac-php.") ((ac-racer 0 2) "available" "auto-complete source of racer") ((ac-rtags 3 23) "available" "auto-complete back-end for RTags") ((ac-slime 0 8) "available" "An auto-complete source using slime completions") ((ace-flyspell 0 1 3) "available" "Jump to and correct spelling errors using `ace-jump-mode' and flyspell") ((ace-isearch 1 0 1) "available" "A seamless bridge between isearch, ace-jump-mode, avy, helm-swoop and swiper") ((ace-jump-buffer 0 4 1) "available" "fast buffer switching extension to `avy'") ((ace-jump-helm-line 0 5 0) "available" "Ace-jump to a candidate in helm window") ((ace-jump-mode 2 0) "available" "a quick cursor location minor mode for emacs") ((ace-jump-zap 0 1 2) "available" "Character zapping, `ace-jump-mode` style") ((ace-link 0 5 0) "available" "Quickly follow links") ((ace-pinyin 0 2 5) "available" "Jump to Chinese characters using ace-jump-mode or avy") ((ace-popup-menu 0 2 1) "available" "Replace GUI popup menu with something more efficient") ((ace-window 0 10 0) "available" "Quickly switch windows.") ((acme-theme 1 0 0) "available" "A color theme for Emacs based on Acme & Sam from Plan 9") ((actionscript-mode 7 2 2) "available" "A simple mode for editing Actionscript 3 files") ((activity-watch-mode 1 4 0) "available" "Automatic time tracking extension.") ((adafruit-wisdom 0 3 0) "available" "Get/display adafruit.com quotes") ((add-hooks 3 1 1) "available" "Functions for setting multiple hooks") ((add-node-modules-path 1 3 1) "available" "Add node_modules to your exec-path") ((addressbook-bookmark 1 0) "available" "An address book based on Standard Emacs bookmarks.") ((ado-mode 16 1 4) "available" "Major mode for editing Stata-related files") ...))
  package-menu--generate(nil t)
  package-list-packages(nil)
  call-interactively(package-list-packages record nil)
  command-execute(package-list-packages record)
  execute-extended-command(nil "package-list-packages")
  call-interactively(execute-extended-command nil nil)