o.filter is not a function

[miksch123]

Describe the Issue

Whenever I launch vscode I get following error message after extensions got activated:
2025-08-06 00:32:24.780 [info] Locating .NET runtime version 9.0.1
2025-08-06 00:32:31.605 [info] [Error - 12:32:31 AM] Microsoft.CodeAnalysis.LanguageServer client: couldn't create connection to server.
2025-08-06 00:32:31.605 [info] TypeError: o.filter is not a function
at t.ExistingPathResolver.getExistingPath (c:\Users\localadmin.vscode\extensions\vscode-dotnet-runtime-library\dist\Acquisition\ExistingPathResolver.js:75:134)
at t.ExistingPathResolver.next (c:\Users\localadmin.vscode\extensions\vscode-dotnet-runtime-library\dist\Acquisition\ExistingPathResolver.js:35:37)
at Generator.next ()
at c:\Users\localadmin.vscode\extensions\vscode-dotnet-runtime-library\dist\Acquisition\ExistingPathResolver.js:12:71
at new Promise ()
at __awaiter (c:\Users\localadmin.vscode\extensions\vscode-dotnet-runtime-library\dist\Acquisition\ExistingPathResolver.js:8:12)
at t.ExistingPathResolver.resolveExistingPath (c:\Users\localadmin.vscode\extensions\vscode-dotnet-runtime-library\dist\Acquisition\ExistingPathResolver.js:33:16)
at c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\src\extension.ts:714:57
at Generator.next ()
at c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\dist\extension.js:2:370014
at new Promise ()
at i (c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\dist\extension.js:2:369762)
at resolveExistingPathIfExists (c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\dist\extension.js:2:384711)
at c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\src\extension.ts:519:36
at Generator.next ()
at c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\dist\extension.js:2:370014
at new Promise ()
at i (c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\dist\extension.js:2:369762)
at c:\Users\localadmin.vscode\extensions\ms-dotnettools.vscode-dotnet-runtime-2.3.7\src\extension.ts:507:208
at Ab.h (file:///c:/Program%20Files/Microsoft%20VS%20Code/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:112:41572)
at Ab.g (file:///c:/Program%20Files/Microsoft%20VS%20Code/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:112:40649)
at Ab.executeCommand (file:///c:/Program%20Files/Microsoft%20VS%20Code/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:112:40556)
at Object.executeCommand (file:///c:/Program%20Files/Microsoft%20VS%20Code/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:164:105653)
at lO.getHostExecutableInfo (c:\Users\localadmin.vscode\extensions\ms-dotnettools.csharp-2.84.19-win32-x64\dist\extension.js:1222:4145)
at r.startServer (c:\Users\localadmin.vscode\extensions\ms-dotnettools.csharp-2.84.19-win32-x64\dist\extension.js:1227:22431)
at l (c:\Users\localadmin.vscode\extensions\ms-dotnettools.csharp-2.84.19-win32-x64\dist\extension.js:1227:17409)
at S4.createConnection (c:\Users\localadmin.vscode\extensions\ms-dotnettools.csharp-2.84.19-win32-x64\dist\extension.js:86:11885)
at S4.start (c:\Users\localadmin.vscode\extensions\ms-dotnettools.csharp-2.84.19-win32-x64\dist\extension.js:86:1864)
at r.initializeAsync (c:\Users\localadmin.vscode\extensions\ms-dotnettools.csharp-2.84.19-win32-x64\dist\extension.js:1227:17922)
at yBe (c:\Users\localadmin.vscode\extensions\ms-dotnettools.csharp-2.84.19-win32-x64\dist\extension.js:1227:38669)

these are my current user settings:
{
"projectsPatterns": ["/bin/Debug/WTS_API_Test.dll", "/bin/Debug/WTS_Ext2Svc_Test.dll", "/bin/Debug/WTSServiceTest.dll"],
"git.enableSmartCommit": true,
"git.confirmSync": false,
"editor.accessibilitySupport": "off",
"diffEditor.ignoreTrimWhitespace": false,
"enableTelemetry": false,
"exclude": "{/node_modules/,/bower_components/,/dist/,/build/,/.vscode/,/_output/,/vendor/,/.min.,/*.map, /bin/,/_WTS.Extensions/}",
"include": "/.{cs}",
"enabledCodeActions": true,
"expression": "(?:\/\/|\/\|\<\!--)[ ]?([A-Z]+)(?: |\:|\(([A-Z\/\d ]+)\)\:)[ ]?(.?)[ ]?(?:--\>|\\/|$)",
"vssolution.trackActiveItem": true,
"git.autofetch": true,
"workbench.editorAssociations": {
".resx": "resx.editor",
".coverage": "default"
},
"NugetGallery.sources": [
"{"name":"nuget.org","url":"https://api.nuget.org/v3/index.json"}",
"{"name":"localnuget","url":"C:/References/"}"
],
"editor.unicodeHighlight.invisibleCharacters": false,
"terminal.integrated.enableMultiLinePasteWarning": false,
"git.ignoreRebaseWarning": true,
"security.workspace.trust.untrustedFiles": "open",
"window.menuBarVisibility": "classic",
"vssolution.solutionExplorerIcons": "current-theme",
"cucumber.features": [
"/Features/*.feature",
"/FeatureFiles/*.feature"
],
"cucumber.glue": [

    "src/test/**/*.java",
    "features/**/*.js",
    "features/**/*.jsx",
    "features/**/*.ts",
    "features/**/*.tsx",
    "features/**/*.php",
    "features/**/*.py",
    "tests/**/*.py",
    "tests/**/*.rs",
    "features/**/*.rs",
    "features/**/*.rb",
    "**/StepDefinitions/*.cs",
    "**/StepDefinition.cs"
],
"redhat.telemetry.enabled": false,
"vstest.dotnet": {
    "output": "bin/debug",
    "framework": "net46",
    "outputFileName": "WTS_API_Test.dll"
},
"nunitTestRunner.projectsPatterns": [
    "**/bin/Debug/*Test.dll",
    "**/bin/Debug/WTSServiceTest.dll",
    "**/bin/Debug/net8.0/TD-Automation.dll",
    "**/bin/Debug/WTS_API_Test.dll",
    "**/bin/Debug/net8.0/*Test.dll"
],
"nunitTestRunner.testsCategory": [
    {
        "projectName": "Foo.dll",
        "categories": [
            "IntegrationTests",
            "FunctionalTests"
        ]
    }
],
"testing.alwaysRevealTestOnStateChange": true,
"dotnet.automaticallyCreateSolutionInWorkspace": false,
"NugetGallery.credentialProviderFolder": "{user-profile}/.nuget/plugins/netcore/CredentialProvider.Microsoft",
"dotnet.unitTestDebuggingOptions": {},
"nunitTestRunner.verboseLog": true,
"nugetpackagemanagergui.packageSources": [],
"editor.largeFileOptimizations": false,
"testExplorer.addToEditorContextMenu": true,
"testExplorer.mergeSuites": true,
"testing.showAllMessages": true,
"testing.openTesting": "openExplorerOnTestStart",
"dotnetAcquisitionExtension.existingDotnetPath": "C:\\Program Files\\dotnet\\dotnet.exe",
"testing.automaticallyOpenTestResults": "openExplorerOnTestStart",
"[csharp]": {
    "editor.defaultFormatter": "ms-dotnettools.csharp"
},
"refactai.addressURL": "https://codeassist.athena.otxlab.net/ ",
"refactai.apiKey": "7e98b820-90fd-4517-95ac-7f6f537ff661",
"nunitTestRunner.discoveryOnStartup": true,
"chat.instructionsFilesLocations": {
    ".github/instructions": true,
    "C:\\Users\\MMIKSC~1\\AppData\\Local\\Temp\\postman-http-request-post-response.instructions.md": true,
    "C:\\Users\\MMIKSC~1\\AppData\\Local\\Temp\\postman-http-request-pre-request.instructions.md": true,
    "C:\\Users\\MMIKSC~1\\AppData\\Local\\Temp\\postman-collections-post-response.instructions.md": true,
    "C:\\Users\\MMIKSC~1\\AppData\\Local\\Temp\\postman-collections-pre-request.instructions.md": true,
    "C:\\Users\\MMIKSC~1\\AppData\\Local\\Temp\\postman-folder-post-response.instructions.md": true,
    "C:\\Users\\MMIKSC~1\\AppData\\Local\\Temp\\postman-folder-pre-request.instructions.md": true,
    "C:\\Users\\LOCALA~1\\AppData\\Local\\Temp\\postman-collections-post-response.instructions.md": true,
    "C:\\Users\\LOCALA~1\\AppData\\Local\\Temp\\postman-collections-pre-request.instructions.md": true,
    "C:\\Users\\LOCALA~1\\AppData\\Local\\Temp\\postman-folder-post-response.instructions.md": true,
    "C:\\Users\\LOCALA~1\\AppData\\Local\\Temp\\postman-folder-pre-request.instructions.md": true,
    "C:\\Users\\LOCALA~1\\AppData\\Local\\Temp\\postman-http-request-post-response.instructions.md": true,
    "C:\\Users\\LOCALA~1\\AppData\\Local\\Temp\\postman-http-request-pre-request.instructions.md": true,
    "C:\\Users\\AUTOMA~1\\AppData\\Local\\Temp\\postman-collections-post-response.instructions.md": true,
    "C:\\Users\\AUTOMA~1\\AppData\\Local\\Temp\\postman-collections-pre-request.instructions.md": true,
    "C:\\Users\\AUTOMA~1\\AppData\\Local\\Temp\\postman-folder-post-response.instructions.md": true,
    "C:\\Users\\AUTOMA~1\\AppData\\Local\\Temp\\postman-folder-pre-request.instructions.md": true,
    "C:\\Users\\AUTOMA~1\\AppData\\Local\\Temp\\postman-http-request-post-response.instructions.md": true,
    "C:\\Users\\AUTOMA~1\\AppData\\Local\\Temp\\postman-http-request-pre-request.instructions.md": true
},
"workbench.secondarySideBar.defaultVisibility": "hidden"

}

Steps To Reproduce

install c# dev tools using mentioned settings and vscode version

Expected Behavior

Extension successfully loads and is able to initialize test loader.

Environment Information

Version: 1.102.3 (system setup)
Commit: 488a1f239235055e34e673291fb8d8c810886f81
Date: 2025-07-29T03:00:23.339Z
Electron: 35.6.0
ElectronBuildId: 11847422
Chromium: 134.0.6998.205
Node.js: 22.15.1
V8: 13.4.114.21-electron.0
OS: Windows_NT x64 10.0.19045

[nagilson]

dotnetAcquisitionExtension.existingDotnetPath is set incorrectly. Sorry, I know it's confusing. Please see https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.vscode-dotnet-runtime. It needs to be an array unless you configure the setting for all extensions.

We should probably error out properly here.

[miksch123]

Many thanks. I honestly could not see the difference since it was working on a company managed laptop and not my dev instance.