Getting this popup error when trying to edit a master page in SharePoint 2010
“Master page editing has been disabled for this site. Contact the site collection administrator to request permission.”
To resolve this problem:
Go to Site Actions and click on SharePoint Designer Settings under Site Collection Administration and enable the desired settings.
– Enable Customizing Master Pages and Layout Pages
There are also more settings you can enable if you want to:
– Enable Detaching Pages from the Site Definition
– Enable Managing of the Web Site URL Structure
Aryan Nava 
Where can I find Site Actions…
Open your SharePoint site and if you have admin access you should see site actions
Does SharePoint foundation have Site collection administration option available in SharePoint Foundation 2010.
If Yes, then where it is available.
Thanks
I’m Site Collection Administrator but I can’t see the option Sharepoint Designer setting in Site under site collection administrator