Activate "Administrator" user for Windows server 2019 machine
This guide assumes you started the steps here: https://help.gameserverapp.com/article/144-allow-access-to-your-windows-server-2019-machine.
Some providers (OVH/SoYouStart) provide your machine with a non-administrator account. This account has limited access, which causes the GameserverApp system to have issues.
To resolve this issue, you need to activate the normal Administrator account.
All instructions below must be executed on the machine you want to host the game servers on.
1. Login in on your Windows Server 2019 machine.
To login on your machine, use a program like Microsoft Remote Desktop.
In this application you enter the IP, username and password you received from OVH/SoYouStart/Hetzner.
2. Open "Computer Management"
3. Navigate to "Users"
4. Administrator account properties
5. Un-check "Account is disabled"
6. Set password for Administrator
Now you should log out / disconnect from your Remote Desktop session, and change the username in the Remote Desktop application to "Administrator".