Hi everyone and thank you for making Greasemonkey! I have been a Firefox user for nearly two decades, and heard of Greasemonkey many many times, but never actually used it – until now. Feels like a great tool to have!

I wrote a simple "hello world" script:

// ==UserScript==
// @name    Hello
// @version 1
// @grant   none
// ==UserScript==

alert('hello greasemonkey');

It works fine, but does not update. When I go to plugins → Greasemonkey → User scripts for this tab → User script options → Update now, I'm getting Error checking for update.

• The error appears under the Update button immediately, as if no network request to my actual script is even attempted
• Nothing is reported in the browser console or in the network requests debugger
• This also happens also if I have @updateURL and @downloadURL in the script

Is there a place where I can see a more verbose output maybe? Or can the error be made more specific?