Error getting a Client Side Page using Get-PnPProvisioningTemplate

Hi

 

I am getting this error when I try and export a Client Side Page using Get-PnPProvisioningTemplate:-

 

powershell.exe Warning: 0 : 2018-03-29 15:45:41.9596 [Client Side Page Contents] [9] [Information] This page is not a valid client side page and can't be extracted. Underlying error = Page About.aspx is not a "modern" client side page. 720ms 673a7b73-01bf-4e81-acc4-399eec9f6d5a

 

How does the Provisioning Engine determine this.  @VesaJuvonen

 

This was working before the March update.  Does anyone know what has changed ?

 

Thanks

 

Nigel