composition disappears in a few seconds after extending the main composition duration

[elay laye5E15]

I have extended the main comp and the rest of the comps I have. I also draged them to end of the timeline, but after pasing the old time(1 min) the images that in the comp are disappearing.

I already search the internt for an answer but I didn't find anything that helped me.

a similar problem to mine is in this link(tessygirl problem's):
https://community.adobe.com/t5/after-effects/all-footage-disappears-after-extending-composition-dura...

thanks

[Rick Gerard]

I see a bunch of nested comps in the main comp. You'll have to figure out which one has the layers that are misbehaving, open that comp, extend the length of that comp, and figure out what is going on in there. Just changing the duration of the master or main comp, will not change the duration of the nested comps(pre-comps).

[elay laye5E15]

I did change the duration of the nested comps, but it still disappear after their original time(I did drag them to the end of the timeline), the photo isn't mine, it's the one in the link I that I attached