"SOURCE IS EMPTY" Error Msg

Hi all,

Suddenly, and out of nowhere my Media Encoder is giving me a "Source Is Empty" error and AE is crashing out when exporting through the Media Encoder.  Literally exported this same file earlier today, don't understand what the problem is.

I've seen some indication online that this could somehow be due to a Firewall issue in Windows?  I'm running the latest version of Windows.

Please help!