Update:   I was able to add 4 users without any errors this morning.   For me this is now resolved (for the time being) I have added the users i needed to. ... View more

Yep, I have 3 VPP accounts setup and I can add them into another VPP, but not the one that i want to. Like you I've tried email addresses which have previously been registered and also using very randomly created ones that have never been used.   And still nothing. Ill keep trying until i hear of a fix.   Thanks ... View more

I too have this problem. Managed to get 1 added but just won't work with the others.   ... View more

Has anyone managed to get this working? I cant. I have all the settings set as per the post above and tried various other variations too after using the referenced webpage, but all i get within iOS settings > Device Management is Unknown Payload against Managed App Settings.   And when i open outlook im just prompted for an email address to start configuring an account.   Thanks ... View more