This is a brief guide which primarily has commands used to resolve issues with AD Connect/ADFS relating to their source anchor to save having to research and find these.

This is for the error within Atria of "Object is not set to an instance of an Object" or "Source Anchor is Invalid".

This is due to a mismatch in AD and O365 of the source anchors of the user. I am unsure how this happens without manual intervention, but I believe it to be an issue with users being deleted from AD, then O365, then recreated, but not federated to begin with. This also could have issues relating to AD Connect.

Below are the commands needed to troubelshoot.

1. Identify if the source anchors are invalid. This has two parts to identify O365 & AD

A) Get the Source Anchor from AD

$UserSamAccount = "b.williams_crc"

$User = Get-ADuser $UserSamAccount -Properties ObjectGUID

$ImmutableID = [system.convert]::ToBase64String(([GUID]($User.ObjectGUID)).tobytearray())

Write-Host "ImmutableID for user $UserSamAccount is:" -ForegroundColor Cyan $ImmutableID

$UserO365Upn = Get-Msoluser -UserPrincipalName "b.williams@atria.local" | Select ImmutableID

$ImmutableID = [system.convert]::FromBase64String(([GUID]($UserO365Upn.ObjectGUID)).tobytearray())

Write-Host "ImmutableID for user $UserO365Upn is:" -ForegroundColor Cyan $ImmutableID

To reset an immutable ID. We need to make the user "Mutable". As the user is expected to be connected and expect the changes from the ADFS server, it currently cannot because it can't find the user, as the Source Anchor is incorrect on each end.

So - We need to convert the user to a mutable user in O365 and make this match. We do this primarily because we believe that Active Directory is the source of truth in the situation of users consuming ADFS. 

$UserSamAccount = "b.williams_crc"
$MicrosoftUPN = "b.williams@atria.local"
$OnmicrosoftTempUPN = "b.williams@atria.onmicrosoft.com"

#Get User from AD and their ImmutableID

$User = Get-ADuser $UserSamAccount -Properties ObjectGUID

$ImmutableID = [system.convert]::ToBase64String(([GUID]($User.ObjectGUID)).tobytearray())

Write-Host "ImmutableID for user $UserSamAccount is:" -ForegroundColor Cyan $ImmutableID

#Set the Immutable ID to match AD retrieved above

Set-MsolUserPrincipalName -UserPrincipalName $MicrosoftUPN -NewUserPrincipalName $OnmicrosoftTempUPN


Set-Msoluser -UserPrincipalName $OnmicrosoftTempUPN -ImmutableID $ImmutableID

Set-MsolUserPrincipalName -UserPrincipalName $OnmicrosoftTempUPN -NewUserPrincipalName $MicrosoftUPN

#Get Immutable ID back from O365