Since this is a 2021 build of a much older engine, always set the Tantra.exe to run as Administrator and in Windows 7 Compatibility Mode .
However, because this specific version string is often used in the titles of suspicious or potentially unsafe file-sharing sites, I want to make sure I’m providing the exact type of "guide" you need.
Right-click the .exe file and select "Run as Administrator" to ensure it has the necessary permissions to modify game windows.