Entities disappearing trouble

I was just wondering if anyone has any problems with entities being removed from their .vmf’s
It’s never happened to any of the .vmf’s i make but since i am taking over someones project their entities all just vanish. I was just curious to see if this is common or just for some random reason. Thanks for hearing me out.

Maybe you have put them into a custom group and forgot to “check” the box next to it ?

Would that remove all static/overlays/decals and player_starts?
Edit: If not checked?

Well, you might’ve clicked on “Entities” group which pretty much does that thing.
Pardon me, I meant it hides entities

Also, Do you have the correct fgd’s. The same one or more that the original mapper was using?