Some Firefox extensions require access to local storage and/or indexedDB, for instance to store data on the user device Firefox runs on.
These extensions may break if cookies are blocked. Extensions like uBlock Origin, uMatrix, or Stylus use the storage and thus require cookie permissions even if they don't set cookies to work correctly.
While some come with fallbacks built-in to overcome this limitation, it is best to address this head on instead as indexedDB usage is usually the better option to whichever fallback solution is used otherwise.
The easiest way to get to the profile folder is to load about:support, and click on the show folder button on the page that opens.
You can check the storage\default directory of the Firefox profile if extensions use indexedDB. If you have folders starting with moz-extension in there, you have extensions that use it and thus require cookie access. Note that the extensions are listed with their internal UUID and not their name. Note that the UUID is randomly assigned during installation. Means: if you uninstall and reinstall, or use the extension on multiple systems, it is different.
Firefox users have two options to address the issue:
Tip: You can manage cookie permissions under Options > Privacy & Security > History > use custom settings for history > Accept cookies from websites, Exceptions. You may use the prompt to add cookie exceptions as well. All that is required is to copy the entire folder name, replace the +++ with ://, add it under "address of website" and set it to allow. (e.g. moz-extension+++23bf26fb-1c8d-40d3-b7c2-798882a0d55c to moz-extension://23bf26fb-1c8d-40d3-b7c2-798882a0d55c)
The Ghacks user.js file for Firefox blocks cookies by default. Users who apply it and run extensions that require cookies may run into issues afterwards. The article highlighted a method to overcome this without enabling first party cookies globally for all sites and extensions in the browser. (Thank you Pants)Advertisement
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.