VSCODE: Cannot read property 'local' of undefined

It is most probably because Code doesn't have privilege to write to the extension folder, which is by default ~/.vscode/extension.

The following command from terminal will fix it:

sudo chown -R $(whoami) ~/.vscode

I experienced the same problem on Windows 10. Permissions in my case were not the problem. Try clearing the contents extensions folder which can normally be found here;

C:\Users\USERNAME\.vscode\extensions

This fixed the issue for me.

If you're looking more details on any error that might be causing your problems, try the following steps to open the developer console to check for errors.

CTRL+SHIFT+P >> Developer: Toggle Shared Process

When I tried this I got the following errors (prior to clearing the extensions folder);

Uncaught (in promise) Error: EPERM: operation not permitted, open 'C:\Users\Ryan\.vscode\extensions\.obsolete'

and

Uncaught (in promise) W: EPERM: operation not permitted, open 'C:\Users\Ryan\.vscode\extensions\.obsolete'
at t.push.scanUserExtensions.then.e (file:///C:/Program Files/Microsoft VS Code/resources/app/out/vs/code/electron-browser/sharedProcess/sharedProcessMain.js:257:223)

Visual Studio Code Windows Error

If you get Cannot read property 'id' of undefined in vscode, there is probably a custom setting in C:\Users\myself\AppData\Roaming\Code\User\settings.json with a reference to a thing that is no more available. In my case it was a changed theme name, so the old name could not be referenced any more.

After removing that setting, the problem was solved.