That didn't work

[David Slight]

I get complaints all the time when users get this message - is there is fool proof way I can tell them to get this fixed? They follow the instructions but they tell me it doesn't help. And yes, my external guests are all @Pernille-Eskebo.com people!!

[#2]

The only way i could think of use Azure B2B and add there domain so there account works.

but if they have another account on your tenant then they will need to have a private window or signout first. or use Profiles in google chrome..

[#3]

I feel your pain and have suffered some times also with Microsoft People ^-^ What have worked always for me is to add the users first as guests in Azure AD and then invite then to the SPO Site....out of curiosity: what kind of site are you sharing with that user?

[#4]

I am only sharing files that are simply part of the Group files. These are the URLs from the browser https://outlook.office.com/owa/?realm=XXXX.org&path=/group/citaa001usapjscottwhitmire@XXXX.org/files https://XXXX.sharepoint.com/sites/citaa001usapjscottwhitmire/Shared%20Documents/Forms/AllItems.aspx David

Here is the equivalent error … cute but just as useless.

[#5]

Have you enabled sharing capability for the Group site using PowerShell?

[#6]

Yes with

Set-SPOSite -Identity https://iasahome.sharepoint.com/sites/citaa001usapjscottwhitmire -SharingCapability ExternalUserAndGuestSharing

I wonder if it has anything to do with the fact that the tenant and SharePoint have different names? SharePoint is 

https://iasahome.sharepoint.com

while Outlook is

iasaoffice.org 

PS: I know this is identifiable information but I am including the full names for clarity here.

[#7]

UPDATE 2: Reconfirming the AzureAD first approach has worked in every case. Manually checking in Azure AD that the SOURCE  is External Azure Active Directory  status (vs Invited User) is required.

The invitation can be resent from Azure AD but it is all a bit manual.  Can we find out why the GroupSubscription.ashx script is not working reliably?  

UPDATE: followed your suggestion and using AzureAD to add a GUEST does in fact add the runes needed. The issue however, is that when signing in to accept the account invitation from Azure AD, I have to sign in with a "Microsoft Account".  Apart from the obvious confusion that every MS person understands (their @Pernille-Eskebo.com email is not a "Microsoft Account") that would seem to be a blocker unless they associate their Microsoft work email as a "Microsoft Account".  

I can't remember if I ever resolved that issue.  Any MS people reading care to give it a try?

Previously:

You suggested "add the users first as guests in Azure AD". Would I have to follow the EXTERNAL naming convention for the USERNAME?

satya_microsoft.com#EXT#@iasahome.onmicrosoft.com

[#8]

That's very weird...my suggestion to add the users directly as guests in Azure AD don't require any naming convention and they should simply added without forcing them to associate their account with a Microsoft account

[#9]

You are right - at that point I had not found the ADD GUEST USER button. It takes care of adding the #EXT# stuff - you can't use that character anyway even if you try :)

[#10]

Mmmm...you don't see an ADD GUEST USER button? Strange...the experience should be like this:
1) Browse the Office 365 Admin Portal
2) Under Admin Center, clic on Azure AD so you will be redirected to https://aad.portal.azure.com/
3) Clic on Acture Active Directory and then on Users and groups
4) Clic on All users and you will see and Add guest user option there

[#11]

Yes, I do have that button/option and realized after posting that it was the way forward. It seems however, that the user still has to CLICK on the acceptance before I add them to the GROUP for everything to be smooth so I have to checking individually; Need some form of flow process that checks regularly and then adds them to the group once the AD status shows as EXTERNAL ACTIVE DIRECTOIRY USER - ie the invite has been accepted.