Please provide reproducible steps for a specific debugger extension.

For Rust, open any *.rs file, press Debug -> Start debug, choose any debugger. Even works if you just press "More".
Same for C++ and *.cpp files.

Please run VS Code without extension code --disable-extensions and then create a trivial node program hello.js:

console.log("hello world");

and start debugging by pressing F5.

Does the error still occur?

@isidorn does the error 'openConfigFile' of undefined ring a bell?

Debugging JS seems to work with extensions enabled.

The exception probably comes from here https://github.com/Microsoft/vscode/blob/master/src/vs/workbench/parts/debug/electron-browser/debugService.ts#L722

@IlyaBizyaev so I would speculate that you are doing this from the purple vscode. Is that correct?
Thought launch can be null there so I think you incovered a potential null pointer which I can push a fix for.

In case you are not doing this for the purple vscode, please Help > Developer Tools, Checkoff the break on uncaught exceptions and paste the exception with the stack trace here.

Please try to run VS Code with just one debugger extension enabled, e.g. Rust.
If this works fine, add the next extension.
I suspect that some extension is causing this.

Well.. I'm not sure what "purple" means here, the bottom toolbar is purple.
Here is the log:

workbench.main.js:sourcemap:9 Cannot read property 'openConfigFile' of undefined: TypeError: Cannot read property 'openConfigFile' of undefined
    at file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:10:494997
    at Object.g [as _notify] (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:62701)
    at Object.enter (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:66048)
    at n.Class.derive._creator._run (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:67876)
    at n.Class.derive._creator._completed (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:67317)
    at Object.g [as _notify] (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:62701)
    at Object.enter (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:66048)
    at n.Class.derive._oncancel._run (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:67876)
    at n.Class.derive._oncancel._completed (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:67317)
    at e.resolveOk (file:///usr/share/code/resources/app/out/vs/workbench/workbench.main.js:9:2438440)
e.doShow @ workbench.main.js:sourcemap:9

The problem is there for C++ with all extensions disabled.

@IlyaBizyaev I have pushed a fix for this such that a null pointer no longer happens. However your root cause will still be there and that is that your extensions do not seem to support no folder vscode (purple) and are thus failing to start a debug session.
You should open a folder and then start deubugging. You can also open issues in the github repositories of the extensions you are using and let them know they should support no folder workspace debugging

hello,
I'm having this problem while running my C++ code
It's just a .cpp file

Hello ask6155,
Please read the discussion above.

Hi @weinand , I am having problems on Linux Mint Serena 18

I followed the instructions in the guide https://docs.microsoft.com/en-us/aspnet/core/tutorials/first-mvc-app-xplat/start-mvc

I installed Code correctly, I ran the dotnet new mvc and I opened the Startup.cs file on Code, I press F5, then a popup request me if switch Node JS or .NET Core. Obviously I switch .Net Core, and appears the message.

Hope this info helps.

Note: As you said, when I run code --disable-extensions and I press F5 to debug It only shows Node JS option.

@ahrherrera hi. If you are running into this issue please use vscode insiders or wait a week for the next stable release.