In Schema Browser, Right-Click a View and Select Alter View
In the Check out options in the tool bar, select Check out so you can Amend the Code.
Amend the Code and press OK.
The Alter View window locks and can't be closed.
WORKAROUND
Check out the object before selecting Alter View.
You can either right-click and Check it out and Check it out using the Check Out options in the Tool Bar
STATUS
Issue Fixed in Version 12
