OpenEMR.ERROR: OpenEMR error - key generation broken during oauth2, so forced exit [] []

Hii, I Need to try oauth2 authorization and FHIR api access .I want to register app through smart-app in openemr.I was unable to creat an app .getting OpenEMR.ERROR: OpenEMR error - key generation broken during oauth2, so forced exit [] [] . below is the screenshot.Also i want to know what does jsonweb key sert uri and key set ??