I have sometimes the same problem.
At the end of the url block (in this case Metar) you can click and the url will change. Then click on the url to confirm the change.
Then try again and there is a good chance that the error has disappeared.
I switched to that, and it worked fine. At the College of DuPage, I looked at whois.com, and their domain name expired on July 31st. This is why they are down.
It works for the METAR, John, but not SYNOP as there’s only the one URL (that I can find), so the error shows when it gets to the SYNOP download.
ROAB has a second URL option but nothing wrong with a third option for upper air data.
Now, here’s a strange thing; I’ve just done a search on Collage of DuPage and the links from Google sent me to a HTTPS site that’s working, as is the digatmos folder: https://weather.cod.edu/digatmos/
Maybe it they’ve just switched from HTTP to HTTPS this weekend and that’s all that needs updating?
Update: The CoD Weather Data Twitter feed has a number of posts over the last 24 hours about website/I.T problems, so looks like this is the problem.
Edit: Read the Twitter posts. Glad I’m not in their IT Dept. at the present time. School has either just started or been in session for a week or so there.
Edit 2: Sent them a Tweet on their domain name expiration.
Not quite the same thing, but an easy fix in your case:
Go to Control Panel > FTP & Connections > Connections > bottom left corner of the window is a tick box for “Rename the file on the server after upload”.
Tick the box and it will upload the files as .tmp and then the server will rename them, this stops the errors when files are in the middle of being uploaded when the page loads.
FYI: The College of DuPage website is still down. Those using the site for SYNOP are going to be out of luck until this gets resolved or Tom chimes in and is able to find another source for that.
There’s been more issues with the website today, according to their Twitter feed.
A post 18 minutes before I posted this says it’s been restored and data is available again.
I just tested WXSIMATE using most or all of the links, with no problems. Maybe it was a temporary problem with the COD site? Are any of you still seeing problems?
While trying to get the updated data (at 19:30 PST), WXSIMATE encountered the following problem while ‘Searching for OZONE from KNMI/ESA’: ‘The ozone data source is apparently not available at the moment.’ :?
I tried a few times with the same negative results - I will try again at a later time.
Seems to be working now, I didn’t have a stalls overnight.
Would it be possible to add the Northern Illinois Uni SYNOP feed to the WXSIMATE download list on the next update, so there’s a backup SYNOP feed?