sitemap not working

my sitemap not working
i always need tu run manullay from adminpanel
why not its auto genrate ?
for better understanding see images

I don't understand what you're trying to tell us from the images.


Do you have a VBSEO Sitemap Generation task in the Scheduled Task manager in the vb admin cp?

simply i want to say (cant download) sitemap
when i run manually sitemap then i can daownload
but next day i cant again download but after run sitemap genrater then i can download

What is the exact error message you receive?

it show me Sitemap file not found
now it showing this http://www.mysite.com/sitemap_index.xml
but after run manually i can download
then it will show this http://www.mysite.com/sitemap_index.xml.gz
where is problem ?
why i always need to run manually

Does it fully complete when running from the task? Is there a progress.dat file on your system? If so, you may need to increase your wait_timeout or memory_limit settings, or remove some sections from the sitemap so it completes faster.