So you need to provide detailed steps of how you installed your server. What your operating system is and everything.
The error you are running into happens when the OAuth2 certificate keys are not found on your hard drive. The system attempts to generate these keys when the API starts up. If it can’t create the keys or there is something wrong with your openssl extension to generate the keys you will run into this problem. If you search the forum for oauth2 keys you’ll find a number of resources that can help you resolve this bottleneck. One such thread is here: