The most common reference for "Products_List_#421.js" or similar zip files relates to automated malware analysis. : Joe Sandbox Analysis
Run the installer and follow the .
If you are seeing "421" while trying to download a zip file from a website, it is likely a server-side error. Download 421 zip
: Access the Zebra ZD421 Support Page to download the latest Windows Printer Driver (v10). Installation Steps : Download the driver from the Downloads tab. The most common reference for "Products_List_#421