I have 2 Macs using Premiere Pro CC, same version. On one of my 2 Mac, i can't open any project who has merged clips in it. It shows this error message. : "this project contained a sequence that could not be opened. No sequence preview preset file or codec could be associated with thi sequence type". It shows this even if there is no sequence in the project. It happens only if i have a merged clip. it could even be a merged audio clip. What can i do?
It sounds like your application is not activated. Try this: Open a new project in Premiere Pro. Choose Help > Decativate > Restart Premiere Pro. Then choose Help > Activate. See if that solves your problem.