I'm submitting my sitemap to Google (site.com/sitemap.php) I've done this previously with Xenforo without any issue, however I checked my setup today and I am getting this error. I have not edited my sitemap. I have not done anything to modify my sitemap. Even visiting my sitemap.php downloads a sitemap-1.xml.gz. Just Google is throwing an error at me. My current version of Xenforo is 1.4.6. I just upgraded from 1.4.5 today just to see if it resolved the sitemap problem. I've attached my sitemap.php in case you want to look at it. As far as I know this is the vanilla normal sitemap.php that comes when you install Xenforo. Let me know if there is anything more that you need from me.