A lot of players have reported getting an error with a lot of different, random numbers whenever they try to create a new save file in the Franchise Mode in Planet Zoo for the first time. This is obviously preventing them from playing the game, but luckily there's a pretty easy fix for it.
The problem that is causing this bug is a save file from the beta version of the game, so this is only something that previous beta players should experience. What you need to do to fix this is to locate the save files for your game, then delete or rename the save files you have. This will allow you to create a fresh save, and you won't get the error the next time you boot up the Franchise Mode.
If the error is still there, try giving your Company another name. This seem to fix it for the rest of the players.