hi， I write a openIDconnect client to authentication my web app from ovirt-engine-4.2.0， this is my engine config : [root@engine ~]# engine-config -a |grep CORS CORSSupport: true version: general CORSAllowedOrigins: https://10.110.128.129 version: general CORSAllowDefaultOrigins: true version: general CORSDefaultOriginSuffixes: :9090 version: general but face some error： Access to fetch at 'https://10.110.128.120/ovirt-engine/sso/openid/authorize?response_type=code&client_id=cloudify&redirect_uri=http%3A%2F%2F10.110.128.129%2Fopenid%2Fcallback&scope=openid%20openid%20ovirt-app-portal%20ovirt-app-admin%20ovirt-app-api%20ovirt-ext%3Dtoken%3Apassword-access%20ovirt-ext%3Dauth%3Asequence-priority%20ovirt-ext%3Dtoken%3Alogin-on-behalf%20ovirt-ext%3Dtoken-info%3Aauthz-search%20ovirt-ext%3Dtoken-info%3Apublic-authz-search%20ovirt-ext%3Dtoken-info%3Avalidate%20ovirt-ext%3Drevoke%3Arevoke-all&state=3kxm6Cp2cRwdhlnbpSu3wBp%2F' (redirected from 'https://10.110.128.129/console/auth/login') from origin 'https://10.110.128.129' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: Redirect is not allowed for a preflight request. engine log(I add log info ) is: 019-04-04 10:16:52,491+08 INFO [org.ovirt.engine.core.sso.utils.SsoUtils] (default task-4) [] engine=======strippedScope [openid, ovirt-app-portal, ovirt-app-admin, ovirt-app-api, ovirt-ext=token:password-access, ovirt-ext=auth:sequence-priority, ovirt-ext=token:login-on-behalf, ovirt-ext=token-info:authz-search, ovirt-ext=token-info:public-authz-search, ovirt-ext=token-info:validate, ovirt-ext=revoke:revoke-all] 2019-04-04 10:16:52,492+08 INFO [org.ovirt.engine.core.sso.utils.SsoUtils] (default task-4) [] engine=======requestedScope [openid, ovirt-app-admin, ovirt-app-api, ovirt-app-portal, ovirt-ext=auth:sequence-priority, ovirt-ext=revoke:revoke-all, ovirt-ext=token-info:authz-search, ovirt-ext=token-info:public-authz-search, ovirt-ext=token-info:validate, ovirt-ext=token:login-on-behalf, ovirt-ext=token:password-access] and I realize this java source not run, i do not find any log in engine.log backend/manager/modules/utils/src/main/java/org/ovirt/engine/core/utils/servlet/CORSSupportFilter.java Regards Hongyu Du