vs.editor.nullLanguage error in the browser console

[afomi]

Environment

• Elixir = 1.14.0
• Erlang = 25 [erts-13.0.4]
• Operating system: OSX
• How have you started Livebook (mix phx.server, livebook CLI, Docker, etc): using mix phx.server (ran mix deps.get and rm'd node_modules and npm installd again)
• Livebook version (use git rev-parse HEAD if running with mix): 33620284b7e4f6727b09e4ed7644e3b827cfd03f
• Browsers that reproduce this bug (the more the merrier): Chrome
• Include what is logged in the browser console:
• Include what is logged to the server console:

Current behavior

• Open a new Livebook and creating a (mermaid) diagram OR opening an existing Livebook an editing a diagram
• Try to update the text, but an error is thrown.

Expected behavior

• See the diagram re-render in the liveview, as the text is edited.

Observed behavior

An error is thrown in the console on every keystroke, when trying to edit a mermaid diagram.

Uncaught Error: Language id "vs.editor.nullLanguage" is not configured nor known

Error: Language id "vs.editor.nullLanguage" is not configured nor known
    at computeConfig (languageConfigurationRegistry.js?0184:94:1)
    at LanguageConfigurationService.getLanguageConfiguration (languageConfigurationRegistry.js?0184:79:1)
    at TokenizationTextModelPart.getLanguageConfiguration (tokenizationTextModelPart.js?eeb5:201:1)
    at TokenizationTextModelPart.getWordAtPosition (tokenizationTextModelPart.js?eeb5:212:1)
    at TextModel.getWordAtPosition (textModel.js?b57f:1420:1)
    at getDefaultRange (inlineCompletionsModel.js?c685:635:1)
    at eval (inlineCompletionsModel.js?c685:559:1)
    at Generator.next (<anonymous>)
    at eval (inlineCompletionsModel.js?c685:20:1)
    at new Promise (<anonymous>)
    at eval (errors.js?fdcc:15:1)

[afomi]

backtracking through commits, this looks good (still works) 2de629d6052f68da7edcaffdc17c3a94f2072453

and the bug appears here (for me, on OSX)
9ff3131

looking into the monaco-editor upgrade from 0.33.0 to 0.34.0

---

update: reverting monaco-editor to 0.33.0 resolved the error for me, for now

[jonatanklosko]

Hey @afomi, thanks for the report! This looks like microsoft/monaco-editor#2962, I just left a comment there. Meanwhile I will downgrade to v0.33.0.