Enable Sharepoint Online Site Scoped Publishing Features

 There appears to be a known issue when trying to active SharePoint Server Publishing Infrastructure within the GUI of Sharepoint Online. This would usually be achieved through Site Settings > Site Collection Administration > Site Collection Features but the page can hang and timeout citing "Sorry, something went wrong Save Conflict. Your changes conflict with those made concurrently by another user. If you want your changes to be applied, click Back in your Web browser, refresh the page, and resubmit your changes."

The workaround to this is to do it via powershell. I had the script below supplied to me by Microsoft after raising a support ticket.

The first thing to do is to enable the PnpPowershell module by running the command below

• Install-Module SharePointPnPPowerShellOnline

With the module installed, edit the script below to reflect the name of your Sharepoint Online site in the $SiteURL variable

#Config Variable
$SiteURL = "https://yoursite.sharepoint.com/sites/sitename"
$FeatureId = "f6924d36-2fa8-4f0b-b16d-06b7250180fa" #Site Scoped Publishing Feature
 
#Connect to PNP Online
Connect-PnPOnline -Url $SiteURL -Credentials (Get-Credential)
 
#get the Feature
$Feature = Get-PnPFeature -Scope Site -Identity $FeatureId
 
#Get the Feature status
If($Feature.DefinitionId -eq $null)
{   
    #sharepoint online powershell enable feature
    Write-host -f Yellow "Activating Feature..."
    Enable-PnPFeature -Scope Site -Identity $FeatureId -Force
 
    Write-host -f Green "Feature Activated Successfully!"
}
Else
{
    Write-host -f Yellow "Feature is already active!"
}

Save the script and execute it from Powershell and this will enable the feature.