Unable to set permission using ECP. Error 5 Multiple objects with Sid S-1-5-32-544 were found

[Gernot_Meyer]

Hi all,

we are using Exchange 2019 on prem and since a week we are unable to set mailbox permission using ECP in any mailbox: We can open mailbox details but when choosing mailbox delegation, a popup "try again later" is logged. also Event 5 in eventlog is raised with "Multiple objects with Sid S-1-5-32-544 were found".

Powershell is working!

I checked all mailboxes getting permission detailes but I am unable to find any problem.

Any hints?

[#2]

Hi @Gernot_Meyer 

try below command and check again 

net stop MSExchangeIS
net start MSExchangeIS
iisreset

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[#3]

Hi@Deleted and thanks for answer.

Server has been rebootet. So that doesn't solve.

[#4]

Maybe try removing the orphaned SIDs from the mailboxes.

Have a look at http://aapbde.blogspot.com/2020/11/find-035-orphaned-sids-and-remove-them.html

[#5]

@Gernot_Meyer We had this occur with 2 shared mailboxes.  Turns out there were 2 objects for user S-1-5-32-544 and 2 objects for user S-1-5-32-548 using Get-ADPermissions (548 may show up in your event log after you fix the 544 issue).  We used the following to determine the existence of the extra object:

Get-Mailbox mailboxid | Get-ADPermission -User S-1-5-32-544 | fl extendedrights,accessrights

which showed 2 objects.  One object was solely for Send As permission.  We used the following to remove the extra object:

Get-Mailbox mailboxid | Remove-ADPermission -User S-1-5-32-544 -ExtendedRights "Send-As"

If you still have the error, repeat using SID S-1-5-32-548 or whatever SID is at issue.