Idmgcext.crx -

If the automatic integration fails, you can manually add the extension. Follow these steps carefully:

IDMGCExt.crx is the critical browser extension file for Internet Download Manager (IDM) idmgcext.crx

On some file-hosting or video sites, the extension can detect multiple links on a single page. It allows you to select multiple files (like a playlist or a series of images) and send them all to IDM at once, rather than clicking them one by one. If the automatic integration fails, you can manually

That's it! Your download panel should be back. Source: Microsoft Q&A If the automatic integration fails