AE CS6 both cache and RAM preview stop after previewing just 1 or 2 frames

[col26000516946i]

Hi All

To fix I've tried all the normal stuff e.g. https://www.schoolofmotion.com/blog/cached-preview 

Issue exists with 

(1) an empty comp

(2) a comp with just 1 shape on 1 shape layer (with no animation, keyframes etc.)

(3) a comp with just 1 shape on 1 shape layer (with a v simple  animation.)

This issue has been gradually getting worse over time but I don't understand why both RAM and disk cache previews affected.
Thanks in advance 🙂

[Mylenium]

Impossible to know. You have not provided any system info or details about the relevant settings for caches and previews.

Mylenium

[col26000516946i]

Hello, please see screen-grabs attached..

Many thanks in advance..

[col26000516946i]

Pls see these screengrabs-

      

[col26000516946i]