Can't install Call of Duty Cold War Zombies?

So my brother recently got the game Call of Duty: Black Ops Cold War Season three on his PS4 (which also includes Warzone and Modern Warfare). The problem is that the Cold War game can't be used to install a zombie, multiplayer or campaign and when I try, I get this message: "An unknown error has occurred"

I've already looked for it on the internet but haven't found a solution. I suspect the PS4 doesn't have that much storage space for this, but I still wanted to ask again how this could be fixed.

For me it is also sometimes the case if you now have a PSN account but no Wi-Fi can be displayed in the upper right corner unknown error or you would be logged out of the PSN

Try to put your Ps4 in safe mode and rebuild database