Error "Login to(Catalog) Unknown error occurred while login" appears when logging into CA Service Management Mobile application using Unified Self-Service (USS) URL.
The authentication type set in Catalog is set to "Artifact Based Single Sign On" but no SSO is being used.
Service Catalog 17.0Unified Self-Service (USS) 17.0
1) Log into Service Catalog as an Administrator > Administration > Configuration > Single Sign-on Authentication
2) Set "Single Sign on Type" to disabled > Save
3) Log into Mobile app using USS URL