My previews for this one project I'm working on stop at 7sec 17 frames. For the life of me I can not figure out why. If I move the work area around it still will only preview 7 sec 17 frames. I tried other projects and they preview fine.
Are you talking about a RAM preview? AE is not like video editors, AE uses your RAM to create the preview. Once your RAM is filled, it stops and plays back. If you want a longer RAM preview then try adjusting the quality from "full" to "half" or "third". This option is found on the bottom of the comp window. Try searching adobes help pages for RAM previews to read up on more info.