Can I find out why this question was deleted and whether there are changes that could allow it to be undeleted? I have found an answer and would like to post that.
The question was automatically deleted by the system because it seemed 'abandoned'.
This is explained in the Help Centre entry, "The Community user deleted my question! What gives?":
If the question is more than 365 days old, and ...
- has a score of 0 or less, or a score of 1 and a deleted owner
- has no answers
- has no active bounty
- is not locked
- has view count <= the age of the question in days times 1.5
- has 1 or 0 comments
- isn't on a meta site
... it will be automatically deleted. (These are termed "abandoned" questions in the code.)
The idea being to clean up questions no one has shown interest in.
Since you want to add an answer, that is clearly no longer true. I have undeleted the question.
I don't know if you can see the question timeline; as its author, I imagine you should be able to. After you originally had posted it, some site members thought it wasn't a good question and suggested it be closed. It hadn't seen any activity for a year, so it was automatically deleted after that.
If you think it's valuable enough, you can always post another question and answer it, though I think it is not on topic on this site. Perhaps this site would be a better fit.