There is a known temporary issue on Firefox that causes a blank or error page when loading Twitter on older versions of Firefox. This issue has been fixed on the latest release (version 81.0.2).
Please update to 81.0.2 to fix this issue. See Update Firefox to the latest release to learn more.
If you're unable to update to the latest version, please try the following temporary workaround:
- Enter about:serviceworkers in the address bar.
- Look for Twitter on the list then click its button.
- Twitter should load the next time you visit it.