[Ahmed Abd el-rahman]

create a black solid then create a hold key frame on the opacity with a value of 0 then after 3 frames change the opacity to 80 then after 3 frames change it to 0 you will notice that all key frames is a hold key frame because we want the opacity to be flicking rather than fading in and out .

after that Press Alt + Click on the opacity stopwatch and write the loop expression

LoopOut(Type=”cycle”)

and that’s it if this not help please inform me

[Ahmed Abd el-rahman]

hi !!! if you are using CS4 try this :

1 – Enable caching frames to disk by selecting the Enable Disk Cache preference

2 – Purge RAM and disk caches (choose Edit > Purge > Image Caches)
For the best performance, select a folder that’s on a different physical hard disk than your source footage. If possible, the folder should be on a hard disk that uses a different drive controller than the disk that contains your source footage. The disk cache folder can’t be the root folder of the hard disk.

if thing changed Inform me Thanks