Media saying offline when it's not offline

I am having this exact problem.  I have created a video using six video files on my hard drive.  I can see them all, they all work.  In the timeline all the videos are imported correctly and I can watch the video using Premiere Pro.

When I export to Media Encoder, I have an error message telling me "Offline media detected and will be encoded using the Offline Media graphic".  It then tells me the name of the missing asset.  But the asset is not missing.  It is there.  I can go to it and play it.  It is seen by premiere pro and plays within premiere pro.  It is not missing.

When I ignore the alert and render the video using Media Encoder, the section of the video using the clip Media Encoder claims is missing has the Offline Media graphic.  If I make a new timeline containing just the video clip Media Encoder says is missing.  I can watch it in premiere pro but Media Encoder still says it is missing.

It is very frustrating.