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Can you please ensure your Downloader is enabled for Chrome, Edge and Firefox. You can check in the Downloader preferences.
Here are steps to open Downloader's Preference.
1. Right click on the RealPlayer logo from the bottom right corner (near your system clock) and click Download Videos.
2. Click RealPlayer Downloader logo from the top left corner and click Preferences.
3. Ensure you see the check mark for Chrome, Edge and Firefox.