Initially this extension didn't work, and there were no error messages in the popup.
Later I checked the background page and found these errors:
_generated_background_page.html:1 Error in event handler for (unknown): TypeError: Cannot use 'in' operator to search for 'skip' in undefined
at subset (chrome-extension://lidjpicdkcgjdkgifmmpalkibjeppdof/background.js:20:18)
at chrome-extension://lidjpicdkcgjdkgifmmpalkibjeppdof/background.js:28:24
3_generated_background_page.html:1 Error in event handler for (unknown): TypeError: Cannot use 'in' operator to search for 'menu' in undefined
at subset (chrome-extension://lidjpicdkcgjdkgifmmpalkibjeppdof/background.js:20:18)
at chrome-extension://lidjpicdkcgjdkgifmmpalkibjeppdof/background.js:28:24