I am trying to test out Single App Mode so we can fulfill a request a user has when their new Ipad comes in. They want it to only allow access to Safari and not allow any websites except the sign in page they set up. I have been able to restrict other sites with no issues, but the Single App mode is causing me issues. I created a Configuration Policy and selected Safari from the Lock to App drop down. When I scope it to my test group, it does attempt to apply, but fails due to "The field “Identifier” contains an invalid value.". Even when I chose "Specify Build ID" and enter "com.apple.mobilesafari" as the build ID, I get the same error. This happens for all apps in the drop down.

I have confirmed the Ipad is supervised and all other settings I set up have applied with no issues. It is just this one thing that will not apply. 

Any assistance anyone can provide would be appreciated.