Elixir-ls and OTP26 not working in VSCode

[dr1ver1]

Is this the right repo?

I don't know

"If the language server fails to launch...". How do I check for this?
Code Completion isn't working. Debugging isn't working. The Test Explorer finds the test file but doesn't find the tests. I don't think the Dialyzer is running...

Environment

"Elixir: Copy ElixirLS Debug Info"

• Elixir & Erlang versions (elixir --version): Erlang/OTP 26 [erts-14.0.2] [source] [64-bit] [smp:20:20] [ds:20:20:10] [async-threads:1] [jit:ns]

Elixir 1.15.3 (compiled with Erlang/OTP 26)

• VSCode ElixirLS version: 0.15.3
• Operating System Version: win32 10.0.22621

OS: Windows 11 Home

Troubleshooting

• Restart your editor (which will restart ElixirLS) sometimes fixes issues
• Stop your editor, remove the entire .elixir_ls directory, then restart your editor
  The only .elixir_ls folder I could find is C:\Users\david\AppData\Local\mix\Cache\installs\elixir-1.15.3-erts-14.0.2\2b00f709b9297a1f57db8c75bf522678\deps\elixir_ls\apps\language_server\test\support\fixtures\.elixir_ls
  I have deleted it... so far it hasn't been re-created.

Crash report template

• Check the output log by opening View > Output and selecting "ElixirLS" in the dropdown. Please include any output that looks relevant. (If ElixirLS isn't in the dropdown, the server failed to launch.)

Installing ElixirLS release v0.15.1
Running in c:/Users/david/Exercism/elixir/rational-numbers
Install complete

• Check the developer console by opening Help > Toggle Developer Tools and include any errors that look relevant.

log.ts:431  WARN [ms-vscode.remote-server]: The viewsWelcome contribution in 'ms-vscode.remote-server' requires 'enabledApiProposals: ["contribViewsWelcome"]' in order to use the 'group' proposed property.
console.ts:137 [Extension Host] ElixirLS: Loading extension
console.ts:137 [Extension Host] ElixirLS: activating extension in mode SINGLE_FOLDER
console.ts:137 [Extension Host] ElixirLS: Workspace folders are Array(1)
console.ts:137 [Extension Host] ElixirLS: Workspace is undefined
console.ts:137 [Extension Host] ElixirLS: creating test controller
console.ts:137 [Extension Host] ElixirLS: starting LSP client for c:\Users\david\Exercism\elixir\rational-numbers with server options Object client options Object
console.ts:137 [Extension Host] ElixirLS: extension activated
log.ts:421  INFO [perf] Render performance baseline is 23ms
console.ts:137 [Extension Host] ElixirLS: registering watcher in rational-numbers projectDir c:\Users\david\Exercism\elixir\rational-numbers
log.ts:441   ERR [Extension Host] Unhandled error in resolveHandler of test controller "elixirLSExUnitTests" TypeError: Cannot read properties of undefined (reading 'capabilities')
	at parseTestsInFileContents (c:\Users\david\.vscode\extensions\jakebecker.elixir-ls-0.15.3\out\testController.js:108:49)
	at controller.resolveHandler [as h] (c:\Users\david\.vscode\extensions\jakebecker.elixir-ls-0.15.3\out\testController.js:20:19)
	at a.I (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:96:17403)
	at a.expand (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:96:14203)
	at e.$w_b.$expandTest (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:103:5888)
	at t.N (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:11199)
	at t.M (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:10965)
	at t.H (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:10046)
	at t.G (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:9122)
	at i.value (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:7952)
	at p.w (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:1902)
	at p.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:2119)
	at f.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:76:13931)
	at i.value (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:127:30341)
	at p.w (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:1902)
	at p.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:2119)
	at f.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:76:13931)
	at MessagePortMain.<anonymous> (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:127:28621)
	at MessagePortMain.emit (node:events:513:28)
	at MessagePortMain._internalPort.emit (node:electron/js2c/utility_init:2:367)
console.ts:137 [Extension Host] Unhandled error in resolveHandler of test controller "elixirLSExUnitTests" TypeError: Cannot read properties of undefined (reading 'capabilities')
	at parseTestsInFileContents (c:\Users\david\.vscode\extensions\jakebecker.elixir-ls-0.15.3\out\testController.js:108:49)
	at controller.resolveHandler [as h] (c:\Users\david\.vscode\extensions\jakebecker.elixir-ls-0.15.3\out\testController.js:20:19)
	at a.I (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:96:17403)
	at a.expand (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:96:14203)
	at e.$w_b.$expandTest (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:103:5888)
	at t.N (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:11199)
	at t.M (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:10965)
	at t.H (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:10046)
	at t.G (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:9122)
	at i.value (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:111:7952)
	at p.w (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:1902)
	at p.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:2119)
	at f.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:76:13931)
	at i.value (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:127:30341)
	at p.w (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:1902)
	at p.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:60:2119)
	at f.fire (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:76:13931)
	at MessagePortMain.<anonymous> (c:\Users\david\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:127:28621)
	at MessagePortMain.emit (node:events:513:28)
	at MessagePortMain._internalPort.emit (node:electron/js2c/utility_init:2:367)
v @ console.ts:137

[lukaszsamson]

OTP 26 is broken on windows. Please wait for patch release 26.0.3 or downgrade to 25. See elixir-lsp/elixir-ls#886