Hello, Thank you for reaching out to the Firefox Support Forum. I understand that you are experiencing an issue with WhatsApp web videos not downloading and playing in Firefox. I'm here to help you with that. To troubleshoot this issue, please try the following steps: Clear the cache and cookies: Go to the Firefox menu, click on Options, select Privacy & Security, and under Cookies and Site Data, click on "Clear Data." Make sure to check the box for "Cached Web Content" and "Cookies and Site Data." Disable extensions: Sometimes, browser extensions can interfere with the normal functioning of websites. Try disabling any extensions you have installed and see if the issue persists. Update Firefox: Ensure that you are using the latest version of Firefox. Go to the Firefox menu, click on Help, and select About Firefox. If an update is available, it will be downloaded and installed automatically. Test in Safe Mode: Restart Firefox in Safe Mode to disable any custom settings or extensions temporarily. Go to the Firefox menu, click on Help, select Restart with Add-ons Disabled, and then click Restart. Disable hardware acceleration: Hardware acceleration can sometimes cause issues with video playback. To disable it, go to the Firefox menu, click on Options, select General, scroll down to the Performance section, and uncheck the box for "Use recommended performance settings." Then, uncheck the box for "Use hardware acceleration when available." After trying these steps, please check if the issue is resolved and let me know the outcome. If the problem persists, provide me with more details, such as the version of WhatsApp web you are using and any error messages you encounter. Additionally, please mention if you have tested the issue in any other web browsers. I hope this helps to resolve the issue you are facing. Feel free to ask any further questions or provide additional information. We're here to assist you. Best regards, Firefox Support Volunteer