When attempting to setup DFFS on our SharePoint Online environment I keep getting an error that says I do not have permission to Add or Customize pages.
I have tried using the CEWP, V1, V2 and App installer all getting the same error. I have enabled customer scripting, have SharePoint Admin credentials, Site owner, modified the site permissions to add the “add or customize pages” permission. when I do the check permission it shows a deny on the add and customize.