So after recently updating my program my RAM preview is not working properly. I have restarted my computer multiple times and a hard reboot and I'm still having this issue. I've uninstalled and re-installed the program as well. I've reset my workspace as well. When I opened up a previous project I did before the update it's working fine. The other thing I've noticed as well is my work area brackets are not working. Instead of the preview ending where the bracket ends it'll continue playing the preview beyond that bracket and won't stop until the preview is finished. I'm not sure how to fix this.
Nobody can tell you anything without proper system info or other technical details like what version of AE or what's involved in your project.