When you create a user on AEM Forms on JEE from adminui and provide it permissions to access forms manager or HTML Workspace, then those users are also considered AEM Forms on OSGi users. When you attempt to login with such a user from AEM Forms on OSGi side, you can encounter an error message similar to the following:
WARNING [com.adobe.idp.um.auth.filter.SecurityFilter] (http-/0.0.0.0:8080-4) Error occured while performing authentication. Marking the authentication as failed.: com.adobe.idp.um.api.UMException| [com.adobe.livecycle.usermanager.client.AuthenticationManagerServiceClient] errorCode:16385 errorCodeHEX:0x4001 message:Exception thrown is NOT a DSCException : UnExpected From DSC chainedException:ALC-DSC-099-000: com.adobe.idp.dsc.DSCRuntimeException: java.net.ConnectException: Connection timed outchainedExceptionMessage:java.net.ConnectException: Connection timed out chainedException trace:ALC-DSC-099-000: com.adobe.idp.dsc.DSCRuntimeException: java.net.ConnectException: Connection timed out
Perform the following steps to resolve the issue: