When issues occur that my affect your users, the Hornbill Service Portal is a great place to publish these issues and to also provide possible workarounds.
Problem Records and Known Errors can be published to the portals with a simple click of a button. Customer facing descriptions of the issues can be added and workaround information included.
Each customer has ability to action the "Me too" option if they are experiencing that issue. This connects their profile directly to the Problem or Known Error giving the Service Desk a view of the impact.