Try restarting in troubleshoot mode. You could also check for malware.

https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems (also deals with hardware acceleration) https://support.mozilla.org/en-US/kb/troubleshoot-issues-related-to-add-ons

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

Note that it is possible that websites no longer support your Mac OSX 10.13 platform and the last Firefox 78.15.0 version for that platform.

You can check the Web Console (Tools -> Web Developer) for messages about content that fails to load.

• https://firefox-source-docs.mozilla.org/devtools-user/web_console/

You can check the Network Monitor to see if content is blocked or otherwise fails to load.

• https://firefox-source-docs.mozilla.org/devtools-user/network_monitor/

If necessary use "Ctrl+F5" or "Ctrl+Shift+R" (Mac: Command+Shift+R) to reload the page and bypass the cache to generate a fresh log.

Hi Terry. Thanks for the speedy reply. I attempted both of those in my search for a solution and neither worked. Troubleshooting mode made no changes at all and there is no interfering malware installed.

Hi cor-el:

The websites that I have been using have all worked up until about two weeks ago when I started getting a “The answer you entered for the Captcha was not correct” whenever I try to log in to these websites, even though there is no Captcha to enter an answer for. I attempted your suggestion of Command+Shift+R and got a “Captcha session reuse attack detected” message with still no way to log in. Everything else on these websites works and loads perfectly with my OS and Firefox, except when I get these Captcha notices.

I looked at the Web Console and noticed that this message appears continuously over and over every second:

Error: 19:56:42.855: ERR_INV_CONTENT: https://public.cobrowse.oraclecloud.com/rely/client/ui/livelook_ui_manager.bundle.js did not resolve Cobrowse.API.DefaultUI.UiManager     fetch https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1     a https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1     a https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1     s https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1 global_launcher.js:1:113985

Error loading UI: https://public.cobrowse.oraclecloud.com/rely/client/ui/livelook_ui_manager.bundle.js global_launcher.js:1:108572

init error: Error: ERR_TIMEOUT     n https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1 global_launcher.js:1:54298     setInitialState https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1     a https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1     a https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1     a https://public.cobrowse.oraclecloud.com/rely/global_launcher.js:1

This is Greek to me and I have no idea what any of it means but I gather that something is failing to launch. When I check the Network Monitor I get this message repeating over and over:

https://public.cobrowse.oraclecloud.com/rely/storage/ll_storage_html5.html?context=37d2w2nyfd2lngvmm06&version=20190515 global_launcher.js.1 (subdocument) Blocked by uBlock Origin.

I have disabled all my extensions and add-ons but it doesn’t help with the Captcha issue at all. I refreshed, I reloaded a new application of Firefox and nothing will help.

Can you post a link to a publicly accessible page (i.e. no authentication or signing on required), so we can check if it work with Firefox 78?

I noticed in your last answer about the Network Monitor: Blocked by uBlock Origin.