SPFx Debugging: Cannot GET /temp/workbench.html

When attempting to debug a recently copied SPFx solution I kept seeing the following error displayed by my browser:

Cannot GET /temp/workbench.html

As per usual, I had entered the following command into the VSCode Terminal window:

gulp serve --nobrowser

Selected the Local workbench profile and clicked on Start Debugging, which attempted to opened the following URL with Google Chrome:


The solution to stop this “Cannot GET” error was to enter the following URL:


This appears to reset the “service, cache or something” causing the error to go away.

Now I can debug as per normal again.