While I was configuring a SPO tenant, i received an error when I tried to navigate to the url “_layouts/savetmpl.aspx” I receveid the error “You don’t have permissions to access to this site”. So what can we do?
Following the post https://albandrodsmemory.wordpress.com/2016/06/06/master-page-gallery-access-denied/ you will need to use PowerShell to solve this problem.
First, open the SharePoint Powershell and type the following:
Connect-Sposervice -url “https://tenant-admin.sharepoint.com”
Set-sposite “https://tenant.sharepoint.com/sites/url” -denyaddandcustomizepages 0
Once this has been executed, you will be able to save the site as a template
Albandrod's Memory 
Reblogged this on SharePoint developers' tips.
LikeLike