Hello!
In Configuration  Advanced Settings (click to collapse)
Use robots.txt file:
the switch of "user robots.txt file" settings don't remain.

access rights on the folder data - 0777
access rights on the file generator.conf - 0666 or 0777

Actually, it's saved but checkbox state displayed incorrectly on configuration page. Please re-download generator package to fix the issue.

Thank you for reporting!
Oleg Ignatiuk
www.xml-sitemaps.com
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