
This happened while trying to add the extension to the browser.
Google help page says: "To protect you while you browse, Chrome only lets you use extensions that have been published on the Chrome Web Store"
The help page futher reads: "If you need to use a disabled extension, you can contact the extension’s developer and ask them to upload their extension to the Chrome Web Store. This will allow you, and other people who use Chrome, to install that extension from the Chrome Web Store, or if you already have it installed, to manually re-enable it from your list of extensions."
Running version of web browser is 'Version 65.0.3322.4 (Official Build) dev (64-bit)'