Why doesn't the game start even though I only want to play offline?

Vi
- in PlayStation
1

I got Gta5 on pc for offline mods. It is currently downloading but 40gb are already loaded, why can't you start offline? Since you could start offline on ps4 without having downloaded it completely, why is that?

Ph

GTA has now got the new Rockstar Launcher on the PC with which you can only start the game online.