Invalid Field name. {7581e709-5d87-42e7-9fe6-698ef5e86dd3}

When you click on your Master Page in Site Settings you get the error mentioned in the title.



The FIX:

In the Site Settings -> Gallery create a new Site Content Type called "My Page Layout"
Select Parent Content Type From: Publishing Content Types
Parent Content Type: Page Layout

Now go to the Master Page Gallery.
Site Actions -> Manage Content and Structure -> Master Page Gallery

Add this newly created content type to the Master Page Gallery.
Settings -> List Settings -> Add From Existing Content Types -> Custom Content Types -> My Page Layout -> Add

This will add all the missing columns back to the Master Page Gallery. We can now safely remove the newly created content type, My Page Layout, from the Master Page Gallery.



Source: http://support.microsoft.com/kb/2000827