Innovator12 installed but eroor:500 occured

Hi, I installed Innovator12 in Windows server 16, I followed the custom installation process and installation is done but when i try to accces through mozilla firefox, Error: Cannot access OAuth Server due to 500 (Internal Server Error) occured. Previously, I have Innovator11 SP12 but i uninstalled due to curious about Innovator12. what can i do to resolve this issue.

Thanking you.