I've posted a discussion on MSO with the same title (but the title was changed). It's about disabling elements that can be clicked but lead nowhere. For instance dead links. Currently, the 404 error page is shown.
One of the comments implied that leaving the elements enabled can actually be positive.
I've always thought that disabling elements that cannot be used was the correct way to prevent users from wasting their time, but maybe there's other evidence. If so, do you know about it?
I think there are two problems here. Firstly, links that go nowhere - which included a 404 page - are wrong, because they imply that a site is broken. If you have nowhere to go, then don't provide a link to go nowhere. As a rule - there are some occasions where it might be acceptable, but it doesn't speak to me of a good site.
However, there is also a problem with disabled links and buttons, because they imply to me that this is a feature that I do not have access to at the moment. It suggests that if I buy a full license, or log in as an administrator, then I might have access to it. If it is never available then it is merely fluff graphics - sometimes acceptable, but needs to be justified as this.
The issue with removing the link entirely is that there might be design problems with this. However, I think it is better to put some work into making the design work with or without the buttons or links than to have links that are meaningless. It is the same rule as anywhere else, that if the graphics are not doing something useful, then get rid of them. As the usual purpose of links is to link somewhere sensible, then to have them there without this requires other justification.
i can't see any reason to enable them. At best leave as read only with note telling the user why they are read only, or better still don't mention at all - they serve no purpose.
If you leave these elements enabled you are essentially inviting the user into a needless click and an error state.
I say no!
Agree here, too. I'm not aware of any formal study of this, but it usually generates a lot of discussion as people see it in different ways.
In the comment cited above, Joel's point is one regarding education and user feedback. His point being showing disabled menu choices can lead to confusion. He's not talking about actions that, when taken, lead to an error or unproductive state - which is what your question refers to.
I can't think of a situation where one would want to leave available an operation that led to a 404. It just looks sloppy and would certainly dent the operator's trust in the application. (Imagine if your web banking app did that, would your opinion of it change?)
As to Joel's point, people will debate this. Let's keep our eye out for UX studies ont he topic.
delelement to give it a red strike-through (or any other appropriate style) could be helpful, that way a user can still go to the location, but are at least prompted that the link is no longer current.