Upgraded the Sitemap app yesterday -- getting error today

I was using 2.5 previously and I upgraded to the newest version yesterday. But now in Webmaster Tools I'm getting:

Your Sitemap does not appear to be in a supported format. Please ensure it meets our Sitemap guidelines and resubmit.

It's always been pretty much plug and play for me. So, I have no idea where to start to dog this down.

I tried deleting and resubmitting once and have gotten the same result. Where should I start on fixing this issue?

Ok, I tried actually looking at the sitemap -- I have three for this forum. Number 1 and 2 show an error and number 3 is working.

Here's the error I get with number one and two:

XML Parsing Error: not well-formed
Location: http://www.myforumdomain.com/forum/sitemap_forum_1.xml.gz
Line Number 1, Column 1:

Nevermind. Sorry to bother you. I deleted the files and reran them and they turned out fine the second time. Seems it was just an issue with that days file. Nothing more than that.

Well, I'm back with this issue. Yesterday I reported this problem. But then I deleted that day's sitemap an resubmitted it and everything was fine. I checked back today and I now have the same problem with Webmaster Tools saying that some, but not all, of the files are invalid format.

Here's a link to today's file that doesn't work: http://www.strat-talk.com/forum/sitemap_forum_1.xml.gz

Yesterday, all the files worked except 1.xml.gz and 2.xml.gz. The Albums and even 3.xml.gz all worked. Today it's 1 and 2 again, plus the album_1.xml.gz file that are bad.

Why does this happen daily with the automatic process? Yet when I delete the files and manually rerun the sitemap application it works correctly?

Also, I have 6 forums. All running this newest version of Sitemap -- this is the only forum with this issue.

It could be timing out.

Try setting the url count per file lower. I recommend 10,000 - 20,000.

Hey Brian,
It's set at 20,000 and my other forums that are 10 times larger than this one. They don't have this issue and they have the same settings.

It might be related to gzip on your server. The first 100 lines are gibberish, but the rest loads fine. a 2nd run (as you did) should clear it out. But if it keeps happening, it's likely an issue of high load when it's running that corrupts it.

Try changing the time of your tasks so all 6 sites aren't running the sitemap at the same time.

Thanks I'll try that. I'm sure they are all running concurrently.

I found the issue. It seems in my task of updating all 6 sites I forgot to run the product upload. So, I had 3.0 files installed but 2.5 product xmls installed. I noticed that the Cron task was different for this one website. So, I uploaded and overwrote the product and it seems all is now well.

I could have sworn I followed through on all six. But I guess I missed one. I've checked and this was the only one I missed.

Thanks Brian. See you around the BBA.

Great Glad you got it straightened out.