The “ACCEPT” options are now up and the game start/running without any errors! THANK YOU SO MUCH, TIS_Ash! And thanks to Beard for keeping an eye out. 💛🧡

Offline installers are updated manually for Beta branches on GOG, sadly that means we're at the mercy of the GOG team for updating them, an email has been sent and I will let you know when I know anything.

Okay, I'll try that again, but this time I'll check to see if any files or folders are left behind. By the way, I think it'll take about an hour for Steam to uninstall the game and download it again. Thanks so much for your reply! 

I appreciate the level of detail you have provided though, I will pass it on to them

Can you try doing a full reinstall? First, uninstall the game, then go to "Steam\steamapps\common\ProjectZomboid" and make sure there are no leftover files or folders there. After that, go to “%UserProfile%\Zomboid” and delete everything there except the “Saves” folder. Then just install the game again and see if that helps.