Hi,
Were you able to check if Media Player has permission to access your music and video folders? Error 0x80070003 usually means the app can’t reach your storage location, often because the folder path is missing, restricted, or on a disconnected OneDrive or external drive. Try opening Settings > Privacy & Security > Media Library Access to confirm Media Player has permission, then make sure your media folders still exist and are connected. If everything looks fine, go to Settings > Apps > Installed Apps > Media Player > Advanced Options > Reset to refresh its settings and clear any broken links. After that, restart your device to apply changes. Are your media files saved locally or synced with OneDrive?
Kind regards,