since the last update (13.7) AE is using up all my memory (12GB for AE, 4 GB reserved for other applications). After that I get the message "Cached Preview needs 2 or more frames to playback". The only solution for me is to restart AE so I get all the memory back, it doesn't work automatically.
Using the purge options do not work any longer.
No one else experiencing this problem?
For persistent causes of this issue, today's bug fix update should solve it.
See the Adobe blog post for more information: A June 2017 Update to After Effects CC Is Now Available | Creative Cloud blog by Adobe
Please let us know if it works for you!