Firefox internal server error 500
Firefox internal server error 500 is an error that usually occurs when trying to load web pages when using Mozilla Firefox. It may mean that there is something wrong with the website’s server. It is also possible that your security software is blocking Firefox or the plug-in process container without informing you. This may occur when changes or updates are detected on your software.
Solution 1. Disable Third-party Application
Firefox internal server error 500 possible cause is a third-party application which is blocking or restricting the Mozilla Firefox from access the site such as antivirus and firewall. Also, some plugin blocking or restricting the site without notice. To prevent this error from appearing, remove the restriction set by the third-party application such as disabling HTTPS Scanning. You could also, disable or remove the plugin, by following the instructions below. Another fix is running Windows on a clean boot, to temporarily disable third-party application installed on your Windows. This included antivirus, proxy server, and firewall.
Disable HTTPS Scanning
Disable / Remove Plugin
- Open Mozilla Firefox.
- Press Shift+CTRL + A keys, to open about:addons page.
- Press the Extensions.
- Disable or Remove all plugin.
Solution 2. Clear Recent History
“Firefox internal server error 500” may also be caused by caches or cookies. Clear the cache and cookies Mozilla Firefox from the sites that cause problems may fix it. Instructions are provided below.
Solution 3. Configure Windows Internet Option
Windows Internet Options configuration might be causing the “Firefox internal server error 500.” The internet option might be blocking the site or a proxy is set. Try to configure it, it may fix the error.
- Chen click Windows Start, type in Internet Option and then click Enter key.
- Go to Connections tab and then click LAN settings.
- Then check Automatically detect settings, and then uncheck Use a proxy for your LAN.
- Click OK.
- Click Security Tab.
- Click Sites.
- The add the website.
- Then click Close.
- Optional: Lower the Security level to Medium.
- Click Ok.
- Try to access the site.