SharePoint Online (CSOM) - The user does not exist or is not unique.

[hyeefung]

What type of issue is this?

other

What SharePoint development model, framework, SDK or API is this about?

SharePoint CSOM

Target SharePoint environment

SharePoint Online

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
• not applicable
• other (enter in the "Additional environment details" area below)

Additional environment details

My application is an C# Web Api (.NET 8) which serves as a middleware between my system and SharePointOnline. The application will be integrating with SharePointOnline by using SharePoint CSOM library (Microsoft.SharePointOnline.CSOM v16.1.21213.12000) from Nuget.

Issue description

Hi. I have a SharePointOnline list composed of 2 columns as below.

• Title (Text type)
• AssetManager (People type)

I have 3 users created in Microsoft Entra ID as below:-
a) User#1

• Principal name: ******@myspotest.onmicrosoft.com
• Display name: John, Doe
• Status: Active & Enabled (MS Entra ID)

b) User#2

• Principal name: ******@myspotest.onmicrosoft.com
• Display name: John, Humming
• Status: Active & Enabled (MS Entra ID)

c) User#3

• Principal name: ******@myspotest.onmicrosoft.com
• Display name: John, Tim
• Status: Active & Enabled (MS Entra ID)

My application is using

SampleCode.zip

to create item(s) to the SharePoint list. I have uploaded the sample code extracted from my application to GitHub, also available in the attachment section. I am using Microsoft.SharePoint.Client.FieldUserValue.FromUser(@DisplayName) to lookup people by DisplayName to populate the AssetManager column (People type). All the 3 users are active but the lookup works for user#1 but not for user#2 & user#3. I received the following errors when lookup for User#2 & User#3.

#User#2

• Error ServerErrorCode = -2130575276
• ServerErrorTraceCorrelationId = "f76070a1-b0da-7000-73f7-37734443b28b"
• ServerErrorTypeName = "Microsoft.SharePoint.SPException"
• Message = Message = "The user does not exist or is not unique."
• Source = Source = "Microsoft.SharePoint.Client.Runtime"

#User#3

• Error ServerErrorCode = -2130575276
• ServerErrorTraceCorrelationId = "206170a1-608d-7000-2916-c89268d414be"
• ServerErrorTypeName = "Microsoft.SharePoint.SPException"
• Message = Message = "The user does not exist or is not unique."
• Source = Source = "Microsoft.SharePoint.Client.Runtime"

Could you please advise why the lookup failed? Do let me know if you need more info. Thanks.

[Ashlesha-MSFT]

Hello @hyeefung,
Thank you for bringing this issue to our attention. We will look into it and get back to you shortly.

[Ashlesha-MSFT]

@hyeefung,
I have reviewed the issue and have a better understanding of the situation. However, I am currently facing the following error while attempting to reproduce the issue using the code you provided:

Could you please provide the necessary authentication steps or guidance on how to properly authenticate in order to successfully run the provided code?

[hyeefung]

Hi @Ashlesha-MSFT. Thanks for prompt feedback and help in looking into this. Unfortunately, I can't share the authentication details for my SPO tenant due to company policy but you may try to follow the steps below in simulating:-

• Link an SPO to the MS Entra ID
• Add multiple new users to MS Entra ID
• Create a SharePointOnline's list with columns as per issue description.
• Login to the SharePointOnline site and you may get the token from browser "Local Storage" (F-12)
• Modify the variable as per sample code as below:-
  a) siteUrl - To your SharePointOnline site URL
  b) token - To the bearer token obtained from browser's Local Storage in "Bearer XXXX" format.
  c) listName - To the name of the list you created in step#3

[Ashlesha-MSFT]

@hyeefung,
Sorry for the misunderstanding. I was asking for the authentication steps, not for credentials.

However, I am still facing a 401 Unauthorized error. Could you please elaborate on this step Link an SPO to the MS Entra ID?

[hyeefung]

Hi @Ashlesha-MSFT.

Could you please help to:-

• Ensure that the credential used has Edit permission on the list? You may login to SharePointOnline by using the credential used to run the sample code and try creating a new list to the list.
• Share which line of code that triggered the 401?

To obtain the token, you may follow the steps below:-

• Login to SharePointOnline by using the credential used to run the sample code.
• Ctrl F + 12 to bring up the dev tools.
• Go to Local storage and select the SharePointOnline domain of yours.
• Try looking up for a key with name starting with "Identity.OAuth".
• The "value" property will be the token required to run the sample code.

Thanks.

[Ashlesha-MSFT]

@hyeefung,
Thank you for the insights,

I am using same type of token, As the tenant is owner he has right to edit the list.

This is line of code where i am getting error
await client.ExecuteQueryAsync();

Thanks!

[hyeefung]

Could you please also help to confirm the following. Thanks.

• Check and confirm the following of Program.cs
  • siteUrl variable is updated to your SharePointOnline site URL accordingly.
  • token variable is updated to your credential's token and it is prefixed with "Bearer " (e.g. Bearer XYZXSSDSDSDSD)
  • listName variable is updated to a list of your SharePointOnline site
• The line # that triggered the exception.

[Ashlesha-MSFT]

@hyeefung,
Thanks for the help

Are you running code again and again to add user?

[hyeefung]

Hi @Ashlesha-MSFT. I do not have the exact simulation steps for this error, but below is what I have tried:

1. Create a new user in Ms Entra ID with Display Name "John, Humming".
2. Try to run the Sample Code to create list item with Asset Manager set to "John, Humming".
3. If the Sample Code working and new list item is added, modify the Display Name of the newly created user (John, Humming1)
4. Try to run the Sample Code to create list item with Asset Manager set to the new Display Name (John, Humming1)
5. If the Sample Code working and new list item is added, repeat step#3 again.

For my scenario, I only have one user with Display Name "John, Humming" and its status is active and enabled but SPO returned "The user does not exist or is not unique." error.

MS Entra ID

Microsoft 365 admin center

[Ashlesha-MSFT]

@hyeefung,
Thanks for explanation,
we were able to repro the issue.

We will log this as a bug, and our engineering team will look into it.

Thank you for your patience!