It might be the case that the website structure changed and this is causing the extractor to fail when it tries to find and download the data on the website.
What you need to do is re-train the extractor with the same url.
Edit your extractor --> Go to Edit Tab --> Advanced --> Train with additional URLs and add the same URL you already had. The extractor will try to match the existing training with the structure. Make sure that all the data is being picked up, if not you can always manually re-train it.
I hope this helps,