either you don't have enough space or you model of phone might be outdated for it to run i think
Or your settings prevent it from downloading
Viewing post in 🔞Five Nights at FuzzBoob's: Definitive Edition comments
If its doing that on your pc then it might something like an anti virus app trying to lock you out
Or if you mean on mobile I would just try clearing your cache of the game and seeing if that works if it doesn't i honestly don't know because I just recently uninstall the game on mobile then reinstall it and there was no problem I can play it without any errors