Possible Firefox bug with the extension, windows only


I get reports from people using latest FF 70.0.1 on Windows only, with extension “I don’t care about cookies” installed, that they randomly see cookie warning not blocked:

Test URL: https://www.paypal.com/uk/signin

It needs to be refreshed at least several times to be caught. I tried it and I was able to reproduce it too (it works in Linux perfectly with same FF and extension version, so it is Windows only), but I’d like someone to confirm it. I’m not sure if it is a Firefox bug although it looks like one, so I haven’t yet reported it.


Anybody, please? Thanks.

I installed the extension in Firefox Developer Edition and wasn’t able to reproduce the issue during 20 reloads of that page, or after disabling and re-enabling. So either it is fixed in Firefox 71 or there is some additional factor needed to reproduce the problem.


I just tried it in Firefox Developer Edition in Windows 10 myself and the problem is still there.

Whenever randomly extension fails to hide the warning, I get “Error: No matching message handler” message in the console pointing to “chrome.tabs.insertCSS()” function.

Funny thing, if I replace it with “browser.tabs.insertCSS()”, the problem is still there but no error is written to the console.