Some Firefox users reported not being able to access the Twitter site after upgrading to version 81 and receiving an “un fixable network protocol violation” error. The only solution is to visit the out servicewokers page and log out of Twitter SW. Mozilla has acknowledged the issue and fixed an issue that is not compatible with Twitter in the Firefox 81.0.2 maintenance update.
Firefox currently offers three tracking protection modes, including Standard, Custom, and Strict, which default to Standard. In Firefox 81, you can’t access a Twitter site if users set tracking protection mode to Strict in Privacy and Security.
In a Firefox 81.0.2 update released today, it said it had fixed the issue: “Fixed an issue that is not compatible with Twitter.com and appears as an intermittent display of the wrong page for network protocol violations.” Users can access Mozilla FTP to download the Firefox 81.0.2 version update based on the connection below this article.