We may face some situation, while editing the site using Sharepoint Designer, it will get open in Contributor mode and we will not be able to edit the site, eventhough we have the Site Collection Administrator (SCA) permission.
By default, Contribute permissions are assigned to the Site Collection Members group. Even though we are part of SCA group, if we are member of Site Collection members the Designer will open in Contributor mode.
To overcome this just disable the contributor settings in SharePoint designer by using the below steps:
1. Open the site in SharePoint Designer.
2. Select the Site Tab -> Contributor Settings.
3. Click on Disable Contributor settings button.
Now we will be able to edit the site.
