Fix NS_E_UNSUPPORTED_LOAD_TYPE (0XC00D1453) fast

Quick answer

Run sfc /scannow in an elevated Command Prompt, then clear your browser cache and cookies. If that fails, uninstall and reinstall the offending media plugin (Silverlight, Flash, or codec pack).

Why this error shows up

This error code (0XC00D1453) with the message "The plug-in does not support the specified load type" means your browser or application tried to load a media file through a plugin that can't handle that specific format or protocol. I've seen this most often in older versions of Internet Explorer or Edge when trying to play embedded Windows Media Player content, Silverlight streams, or Flash video. The plugin itself might be corrupt, outdated, or missing a required codec. Sometimes it's a corrupted cache that stores bad plugin data. This tripped me up the first time too—I spent an hour chasing codec packs before realizing a simple cache clear fixed it.

Fix steps

1. Close all browser windows and media players. This releases any locked plugin files.
2. Run a System File Checker scan. Open Command Prompt as Administrator (right-click Start, choose "Command Prompt (Admin)" or "Windows Terminal (Admin)"). Type sfc /scannow and press Enter. Wait for it to complete—this repairs corrupt system files that might affect plugin loading.
3. Clear your browser cache and cookies. In Edge, go to Settings > Privacy, search, and services > Clear browsing data. Choose "All time" for time range, check "Cached images and files" and "Cookies and other site data", then clear. In Chrome, it's the same path. In Firefox, go to History > Clear Recent History > Everything.
4. Reinstall the media plugin. If you're using Silverlight, download and install the latest version from Microsoft's site (even if you think you have it). For Flash Player, get the latest from Adobe's archive (note: Flash is end-of-life, so consider migrating to HTML5). For Windows Media Player plugin, go to Control Panel > Programs > Turn Windows features on or off, uncheck "Media Features", reboot, then re-check it.
5. Reset Internet Explorer settings. Open Internet Explorer (yes, it's still there in Windows 10/11). Go to Tools (gear icon) > Internet options > Advanced tab > Reset. Check "Delete personal settings" and reset. This clears all plugin-related state.
6. Disable and re-enable the plugin in your browser. In Edge (Chromium version), type edge://plugins in the address bar (or chrome://plugins in Chrome). Find the offending plugin (like Silverlight or Flash), disable it, restart the browser, then enable it again.

Alternative fixes if the main ones fail

• Use a different browser. Some plugins only work in Internet Explorer mode (Edge has IE mode). Try opening the page in Edge with IE mode enabled: click the three dots > Reload in Internet Explorer mode.
• Reinstall codec packs. If it's a local media file, install a combined codec pack like K-Lite Codec Pack (Basic is enough). This often resolves load type issues in Windows Media Player.
• Check for Group Policy restrictions. If you're on a work computer, your IT may have blocked certain plugin load types. Run gpedit.msc (Pro editions only), go to Computer Configuration > Administrative Templates > Windows Components > Internet Explorer > Security Features. Look for "Restrict ActiveX Install" or "Turn off loading of specific plugins". If set, contact your admin.
• Perform a Clean Boot. Press Win+R, type msconfig, go to Services tab, check "Hide all Microsoft services", click "Disable all", then go to Startup tab > Open Task Manager and disable all startup items. Reboot. This isolates third-party conflicts that might block plugin loading.

Prevention tip

Keep your plugins updated. Silverlight hasn't been updated since 2019 (it's deprecated), so migrate to HTML5 players where possible. For local media, stick with VLC Media Player—it handles almost any load type natively and doesn't rely on system plugins. Also, clear your browser cache weekly—it's a low-effort habit that prevents a whole class of plugin errors.