When attempting to either rollback or incorporate live on a GPO that is noncompliant the below warning may occur:
"Objects must be in the available state to perform compliance actions (rollback, and incorporate live). The following objects are not available and will not be processed."
If the GPO is in a noncompliant state, the Status column will display this status and not the underlying status that it is in (for example, checked out or available). Go to the properties of the GPO) and check the status on the General tab. If the GPO is Checked Out then right click on the GPO and chose "Undo Check Out". This will change the GPO into an Available state and then compliance actions can be performed.
Enhancement ID TF00698115 has been submitted to add an additional column to the console for compliance status. This will allow the underlying status to be displayed, in addition to the non compliance status.