Right-click on RagniteRO.exe and tick the box next to Run as Administrator.
Right-click on RagniteRO.exe and set its Compatibility mode to Windows XP (Service Pack 3).
Right-click on RagniteRO Patcher.exe and tick the box next to Run as Administrator.
Make sure the game is NOT installed in Program Files, My Documents or Desktop.
Disable Antivirus and Firewall software before installing and patching the client.