[Qgis-user] After upgrade none of the TIFF imagery is visible

[jon]

I was using QGIS 1.8 and upgraded to 2.8.1.  When I open an old Project, 
the image layers are present in the list on the left, but none of the 
imagery is visible on the map.  Not sure how to bring the imagery back.

Also, I'm overwhelmed by all of the programs that were installed: Grass, 
Desktop, Browser, SAGA.  Is there a brief description explaining which 
to use under various circumstances?

Thanks!

Jon