Add your NVR's IP address to the "Internet Explorer mode pages" list. Reload the camera page in IE Mode and reinstall the plugin. FAQ/Manually Download Internet Explorer Plugin - DahuaWiki
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: If the video still fails to load, try temporarily disabling your firewall or adding an exception for the file in your antivirus settings. Is it Safe? Webplugin.exe Download
Since IE is no longer available on Windows 11, you must use Edge's IE Mode: Add your NVR's IP address to the "Internet