Removing fields - unable to process your request

Removing fields - unable to process your request

I keep getting a message that says "Unable to process your request" when i try to remove an unwanted field.
 
I go to customization / layouts and drag the item to the "List of Removed Fields" section. When i click save i get the "unable to process your request" message.
 
My profile is set to administrator.
 
Can someone help me please?
 
Glenn