You haven't given enough details about your system. We don't even know if it's Windows or Mac? And, out of them which OS? Windows 7? 8? Mavericks? Snow Leopard?
We don't know what version of AE you're running. Is it 12.2.0? 12.1.0? 11.0.4? 11.0.3? 10.5.1?
Has this worked before? If so, when did it stop?
Are you in a networked environment? Do you manage your machine or does IT take care of it?
Really sorry about that, Szalam. here are the details: Mac OS X 10.8.5. Running After Effects CC with most recent updates. The Ram preview did indeed used to work fine when using After Effects. 3 weeks or so ago I uninstalled After Effects and reinstalled because Media Encoder would not work part of the time either (couldn't import right into Media Encoder from After Effects. That too only works half of the time still). Here in the past 2 weeks or so Ram preview does not preview the full work area most of the time. I did not do anything differently that I can recall. Since having issues, I upgraded Ram to 16 from 8 but still not previewing like it used to. I manage my own machine- not on a network environment.
Thank you, Szalam. I will take a look at doing that.