This screenshot represents an error I've received numerous times where I've edited a Stored Procedure only to have the IDE tell me there's an error (when there is not) and prohibiting me from saving the changes. Note in this example, I added "in_password", which triggered this error stating out_result doesn't exist, when it does.
Note copying the contents of the window, closing, re-opening the Stored Procedure, Pasting and Applying changes works fine. There are no errors or syntax issues.