I keep hitting Google search results to this page where somebody asks a question, nobody has an answer, and at the bottom it says:
“This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.”
I’m sure this is well-intentioned, but it’s a terrible thing to do. It means that everybody who ever clicks a search result and lands on that thread will have the same experience: reading the question, finding that there isn’t actually an answer, and grumbling at the waste of time.
Leave questions open. There have been countless cases where I’ve hit that, then found the answer with further research, and wanted to post the answer to the thread for the next person who searches their way there, but been unable to.
The most important feature of open forums is for the countless future people with the same problem–not just the one random person who happened to ask the question–so being able to add answers is still vital, even if it’s an old post and the original poster no longer cares.