Mozilla released Firefox 81.0.2 today, October 13, 2020, on the fixed channel for Windows, macOS, Linux and Android with a fix for a known issue that prevents Twitter from loading.
The problem with a large number of Firefox users caused the web browser to display blank pages or errors instead of loading Twitter pages in both desktop as well as mobile Appliances.

Firefox 81.0.2 release notes state that this release "Fixed an incompatibility with Twitter.com manifested by intermittent display of an error page."
You can update to Firefox 81.0.2 by going to Options -> Help -> About Firefox and the browser will automatically check for the new update and install it when available.
You can also download Firefox 81.0.2 from the following links:
- Firefox 81.0.2 for Windows 64-bit
- Firefοx 81.0.2 for Windows 32-bit
- Firefοx 81.0.2 for macOS
- Firefox 81.0.2 for 64-bit Linux
- Firefox 81.0.2 for 32-bit Linux
- Firefox 81.0.2 for Android
Affected users after updating to Firefox 81.0
Although Mozilla did not "share" the Firefox versions affected by this issue while users stated that Twitter loading errors started appearing after updating to Firefox 81.0 last month.
On devices where the web browser failed to load Twitter, users saw the error "The site at https://twitter.com/ encountered a network protocol breach that could not be fixed."
"The page you are trying to view could not be displayed because a transmission error was detected data", Also reported the error. "Contact the owners of the website to inform them about this problem. "
If you cannot update version 81.0.2 immediately, you can follow this procedure to resolve them errors that appear when you try to open Twitter:
Type about: serviceworkers in the address bar (as you can see in the screenshot below)

Browse Twitter in the list, and then click Unregister.
Twitter will load the next time you visit it.