Empty XML sitemap

[coolbits]

Hi!
Sorry, apologize for my English, I write with a translator.
Standalone Sitemap Generator (PHP) v8.1
An XML sitemap is created, and it is visible in the preview on the "VIEW SITEMAP" page.
But when i click on the link to the sitemap - the XML-sitemap is empty.
I will be grateful for your help

[XML-Sitemaps Support]

Hello,

do you have a file named .htaccess in domain root folder? If yes, what is it's content?