plugins cannot create site map

You will need to seek support from the plugin developers. You can do that here: https://wordpress.org/support/plugin/google-sitemap-generator/

Understood. This likely means google made a change to their site maps api and you will need to contact the plugin devs of those two plugins to get them to fix their plugins. The only other thing I can think of that could be causing the issue is a conflict between your theme and the plugins you are using.

No question is silly Stef. I had missed that he was using Yoast after disabling the other plugin else I’d have actually asked the same question.

Your XML sitemap is already public (add this to google webmaster):
http://www.autobooks-aerobooks.com/sitemap_index.xml