sitemap crashes

[delu.an1]

when I create the sitemap suddenly crashes and does not create anything, I have to create it in multiple passes, sometimes it gives me an error message even when it should automatically create a sitemap, what happens?? the site is [ External links are visible to forum administrators only ]
thanks

[XML-Sitemaps Support]

Hello,

it looks like your server configuration doesn't allow to run the script long enough to create full sitemap. Please try to increase memory_limit and max_execution_time settings in php configuration at your host (php.ini file) or contact hosting support regarding this.