Hey Cathy,
I'm not sure it is exactly the same thing. But I recently updated a website, and in Google Search Console (GSC), entered the path to the sitemap (https://www.domain.com/sitemap.aspx). And the status there was: Couldn't fetch.

When researching the problem I saw this post .
some say that the 'couldn't fetch' status is a bug in the new GSC, and that thit status means pending.
One offered this, which I found helpful
"Alas there is no real way (that I know of!) to tell between them.

But can try using the URL Inspection on the sitemap url. it SHOULD say not indexed (it's a sitemap not a page, so shouldn't be indexed!), but can use the Live Test, to check if Googlebot CAN fetch it!

Again as its a sitemap, NOT a page, DON'T use the 'Request Indexing' button!

If Google can fetch it, it's most likely just Pending, which case just wait. "

the console could open the Live page, so i assumed it was pending. And now checking again, I see the status in GSC is Succcess.

Hope this helps,
Sytske van Hasselt

Same problem here... but after 2 weeks it still says can't fetch and unknown type...

Did you solve the problem?

Please help?

I just tried this and to me this does seems like an issue of google as I can open the url + it's not generating any errors in other sitemap test tools.
 

Thanks Timo!

That was also my conclusion but ofcourse this doens't help te customer.
When you rename the file to sitemap.xml  Google does except the sitemap.

I also don't understand when I why some websites sitemaps are accepted and other websites give an error on submitting /sitemap.aspx.
It isn't consistent

yes, that is strange..

After a week it still shows: can not fetch (unknown type)

Is there a way to report this issue to google?
I assume it's a problem/issue in Google Search Console not in DNN?

I just noticed someone addes this Bug to DNN-github: 
https://github.com/dnnsof...Platform/issues/3277
"Sitemap.aspx is not longer accepted bij Google Search Console"
So apparantly, this is a broader issue.

I also found this remark on Webmasters Stackexchange: 
"After seven years of using a sitemap with an ASPX extension, we have had our sitemaps stuck in a "Couldn't fetch" status for weeks. When we added a rewrite rule that forced sitemap.xml to the aspx page, our sitemap was fetched and processed within a day. It may not be required, but it appears to have some priority."

I know this doesn't help, but it might explain. And: the sitemap which I previously submitted succesfully, is now again at 'couldn't fetch'... 

ok so this sounds like Google does not accept an alternative extension any more..

It seems that Google is no longer accepting the .aspx extension. Does anyone know if the DNN developers aware of this problem and if a fix is on the development roadmap?