Check the composition. Showing us the render cue tells us nothing about your project or your problem.
You will see an empty icon in the timeline:
And color bars in the project panel:

If you can't find it check the flow chart. When it is expanded you'll see color bars in the flowchart:

If Case.png was your missing file you could right-click in the flowchart select Reveal In Project. That would take you to the Project Panel where you could right-click and select Reveal In Finder (folder). Then you could search for the missing file and put it in the correct folder.
These are standard troubleshooting techniques that you should be very familiar with. The flowchart can save you a lot of time.