Environment data

• OS and version: Mac OS 10.14.1 (18B75)
• Python version (& distribution if applicable, e.g. Anaconda): 3.7.3

Expected behaviour

Debug configuration is created.

Actual behaviour

Error message Cannot read property openConfigFile.

Steps to reproduce:

1. Checkout the sample repo
2. Follow steps
3. On the "Add Debug Configuration" step, the error occurs.

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

N/A

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help; turn on source maps to make any tracebacks be useful by running Enable source map support for extension debugging)

workbench.main.js:2365 TypeError: Cannot read property 'openConfigFile' of undefined
    at handler (workbench.main.js:4662)
    at c.invokeFunction (workbench.main.js:1385)
    at Proxy._tryExecuteCommand (workbench.main.js:3015)
    at r.then.i (workbench.main.js:3014)
onDidNotificationChange @ workbench.main.js:2365
workbench.main.js:238 [Extension Host] Python Extension: Cached data exists getEnvironmentVariables, tasks (at r.logInformation (/Users/md65733/.vscode-insiders/extensions/ms-python.python-2019.4.12954/out/client/extension.js:1:16757))
workbench.main.js:238 [Extension Host] Python Extension: Cached data exists getEnvironmentVariables, extension-output-#3 (at r.logInformation (/Users/md65733/.vscode-insiders/extensions/ms-python.python-2019.4.12954/out/client/extension.js:1:16757))
workbench.main.js:2365 TypeError: Cannot read property 'openConfigFile' of undefined
    at handler (workbench.main.js:4662)
    at c.invokeFunction (workbench.main.js:1385)
    at Proxy._tryExecuteCommand (workbench.main.js:3015)
    at r.then.i (workbench.main.js:3014)
onDidNotificationChange @ workbench.main.js:2365