Yes, JoomSEF is allowed to access the site URLs and the robot.txt file is fine. The sitemap generator in this module worked fine when I first purchased it. Then I updated to the newest version and it stopped working. I uninstalled it, reinstalled the older version I'd purchased and redid all the settings and it's still not working.

Ah hold on. I might have understood you wrong before. You just pressed the "generate sitemap" button only? Please first try to "index" some url's. Checkbox the url's you would like to have in your sitemap. Make sure that the dropdownlist at the top is mentioning "Index" and press "Proceed" on the right side of the dropdownlist.

After a few second you get a similar notification as you had before. Now press "Generate XML". And the checkboxed (and indexed) url's should be in your sitemap.

I did index some pages first before pressing Generate and it still crashed.

Mmm, don't know then, sorry :-(

I have exactly the same problem. The support and number of bugs (I started another topic, beacause first joomsef suddenly switched my site from blog-layout-view to category view and then after update to the newest version does not recognize that it is the paid version) is really annoying for that it is a commercial component!

I think for my next clients I will not buy it anymore...

I'm have the same problem. Does someone know how to fix this? Thank you.