after I precompose a piece of the video disappears, why is this happening?
Impossible to make much sense of it. Such a small video barely allows to recognize anything and it's realyl not clear what's going on. Start by flushing your caches. anything else will require better information.
I apologize for the quality, I have attached other video, maybe it will have better quality. I did everything according to your advice, but the problem did not disappear
Two of your layers (bottom two) are parented to a layer (31) you are leaving out of the pre-comp. Also you have several adjustment layers. When you pre-compose you are losing all of the translation and effects from those dependencies. That's probably where you problem is. Also could just be a memory/cache issue as Myl said.
thanks for the advice! as I understand it, I need to make a precomposition of all layers, right? if so, then unfortunately the problem has not disappeared. I will try to clear the cache
Not necessarily. And I don;t know what you mean when you say "ALL" layers. You need to include any layers that other layers may be dependent on. But in general you would to be sure you're not breaking any dependencies in the compositiopn you're taking them OUT of. Like myl said. You need to be very specific. Show all the layers modified properties. What adjustments you're using how they are affecting layers. Even what's in your other comps could be affecting it.
It's not a catch-all rule to say "all layers have to be included" "ALL" is a variable, it means different things at different times.
It was just a way to try and isolate where your problem is so you can start looking in the right place. Then, hopefully you can start fixing whatever needs to be fixed.
Could be simple...could be frustratingly complicated and make you want to start all over.
You need to show all of your relevant settings. relationships...basically anything you have modified. With all you've got going on in that comp it's going to be A LOT. Fingers crossed that it's as simple as clearing your cache.
thanks for the help! I tried to do everything as you say, but unfortunately it did not help. I started all over again and this problem no longer exists!