I am having the same problem on Firefox 81 (Kubuntu 20.04) with the error,

Oops."

The site at https://twitter.com/home has experienced a network protocol violation that cannot be repaired.

The page you are trying to view cannot be shown because an error in the data transmission was detected.

Please contact the website owners to inform them of this problem.

I have to flush the cache ever time I go to a new page on Twitter. You can do this with ctrl + f5. (eg; hold down the Ctrl key and push the F5 key). Hope that helps.

Have you tried: https://twitter.com/

Please explain the problem in detail. What happens? What is/are the exact error message(s) ?

Do you get a message about a "network protocol violation that cannot be repaired"? In that case, please try this:

(A) Open the Serviceworkers page

Type or paste about:serviceworkers in the address bar and press Enter/Return to load that internal page. These are scripts that sites have left running in the background in Firefox.

(B) Unregister the Twitter worker

If you find one for Twitter, click its Unregister button.

If you do not find one for Twitter, try clearing Firefox's web cache: How to clear the Firefox cache. Note: in that dialog, Firefox may preselect to clear both cookies AND cache. Uncheck the cookies box for now, you can try that later if needed.

All I did to fix the problem was to go to settings and changed the tracking from strong to standard tracker blocking and the problem was solved.