@Frisbee head: I recommend starting a separate thread specific to the issue you're having with lost renders. That way others who are hitting this problem have a better shot at finding the thread. If you do so, please be as specific as possible about the types of files, effects, etc. in your sequence. Does the Events panel show any errors?
Of course, if the preview renders are getting lost chiefly if not entirely as the result of a recurring crash, then the first order of business is to get a handle on that crash. Again, a separate thread is the best bet. For that thread, please specify the following:
- if you are working with a CS6 project that you opened in CC? If so, can you repro with a new project created in CC?
- Are you hitting the crash only in one project or only with one sequence? If so, you could be dealing with a corrupt project or sequence.
- Do you get an error dialog or crash report?
One rather unrelated point: In the second sentence of your first post in this thread, you wrote the CC is "effectively without serious additions." Are you asserting that the CC release is lacking in new features? If so, I don't think that's a fair assessment, and as evidence I give you these two pages:
- http://helpx.adobe.com/premiere-pro/using/whats-new.html
- https://www.adobe.com/products/premiere/features.html
Of course, you may not have much use for the new features and workflow enhancements, but that's doesn't equate to the CC release being light on innovation. (To say nothing of being potentially counterproductive for your immediate purpose of getting assistance with the issues your encountering.)