How force something to load, and only after run script?

I’m want make custom loading screen, but the problem is in thing that some things aren’t loaded from ScreenGui, and due to this, scripts are erroring. How I can force script to wait until everything loaded? (WaitForChild don’t work)

You can use ContentProvider:PreloadAsync, preferably in ReplicatedFirst

You can make a script that loads all the frames just as the player joins.