The Internet Download Manager (IDM) is a program that allows you to perform batch downloads and speed up downloads. Use the steps to below to make sure the IDM is enabled on Firefox:
• Download and install the latest version of IDM software
• Restart Firefox to complete the browser integration.
• Use the Internet Download Manager menu bar and go to ‘Downloads’ then click ‘Options’.
• Confirm that there is a checkmark next to "Mozilla Firefox"
• Go to the "Customize IDM Menu Items in Context Menu of Browsers" and click "Firefox and other Mozilla Based"
• Enable "Download with IDM" and "Download All Links with IDM"
• Go to the add-ons section and make sure the "IDM CC" extension is enabled
If the IDM is still not fixed call the Mozilla Firefox customer care number for additional technical support.