[BUG] Unable to Preserve System Fields (Author, Editor, Created, Modified) During Site Collection Migration

[I-BhushanSalunkhe]

Reporting an Issue or Missing Feature

We are attempting to functionally migrate data from one SharePoint Online site collection to another by technically recreating equivalent list items in the target site collection using PnP PowerShell.

During migration, when we try to preserve system-managed fields such as:

• Author
• Editor
• Created
• Modified

the cmdlet fails with the following error:
The specified user could not be found.

Architecture Context

Current (Source) Architecture

• All transactional and master data reside in a single site collection.

New (Target) Architecture

• One primary site collection acts as the user interface and hosts globally applicable master data.
• Market-specific subsites store market-level master data and transactional data.
• SPFx web parts are used to enforce market-based data segregation at the UI layer.

Migration Scenario

• We are migrating historical data from the old architecture to the new one.
• All required users, permissions, and market-level access configurations have been pre-provisioned in the target environment.
• Despite this, when explicitly setting system fields during item creation/update, the migration fails with a user resolution error.

Permissions Tested (App-Only)

We tested the migration using the following app-only permission configurations:

• Sites.FullControl.All + User.Read.All
• Sites.Selected (Microsoft Graph & SharePoint) with FullControl on both source and target site collections + User.Read.All

The issue occurs consistently under both permission models.

Expected behavior

The migration should allow preserving system-managed fields (Author, Editor, Created, Modified) when:

• The referenced users exist in the tenant
• The application has sufficient permissions to read users and write list items

Actual behavior

The cmdlet throws:
The specified user could not be found.

even though:

• Users exist in the tenant
• Users have access to the target site/subsite
• The app has FullControl and User.Read.All permissions

Steps to reproduce behavior

• Ensure all configurations are in place in target site collection including users and permissions.
• Create an item in a list in target site collection by reading values from source site collection using Add-PnPListItem
• Try to update item using below code

Set-PnPListItem -List "TargetList" -Identity $newItem.Id -UpdateType SystemUpdate -Connection $marketConnection -Values @{
    "Created"  = $oldItem.FieldValues["Created"];
    "Modified" = $oldItem.FieldValues["Modified"];
    "Author"   = $oldItem.FieldValues["Author"].Id;
    "Editor"   = $oldItem.FieldValues["Editor"].Id;
}

What is the version of the Cmdlet module you are running?

3.1.0

Which operating system/environment are you running PnP PowerShell on?

• Windows
• Linux
• MacOS
• Azure Cloud Shell
• Azure Functions
• Other : please specify

[KoenZomers]

@I-BhushanSalunkhe The issue here likely is that the users you're trying to set as an author have not visited the site yet at the point of migrating. This means they do not have an entry in the UserInformationList yet, which causes the error you're seeing. Can you try running New-PnPUser first for the user and then performing your Set-PnPListItem command? This should fix it. Be aware that New-PnPUser does an EnsureUser call which is quite heavy on the backend, so only use it the first time the user has not been visiting the site yet. For this reason we also cannot add this to our code in the Set-PnPListItem cmdlet to be done by default.

Let us know if this resolves the issue.