Website Title & Description not updated

Hello team,

I have an issue since I have installed the “Google XML Sitemap Generator for WordPress 4.0.4”.

Currently when searching in google the new website Title inserted is not updated and the description inserted in the general settings is not showing up, it is blocked:

https://www.google.de/?gfe_rd=cr&ei=FUVaU7vqAsKI_AbDmoGwCQ#q=gustavo+malet”

The results of the search shows the following message for the description:
“A description for this result is not available because of this site’s robots.txt”

But the reading setting are correct, so no idea why.

Another issue happening, which I think is related with this, is when posting a photo from the gallery in a social media. The description of the post is crazy:

You may use these HTML tags and attributes: <​a href=”” title=””> <​abbr title=””> <​acronym title=””> <​b> <​blockquote cite=””> <​cite> <​code> <​del datetime=””> <​em> <​i> <​q cite=””> <​strike> <​strong>

This is the link posted, so you can also preview it:
http://gustavomalet.com/?attachment_id=709

Maybe it is important, this message appears only when posting photos from the gallery, but when posting a new blog entry, the description is absolutely correct.

Currently in the GWT I dont get any error message, URL blocked or crawl errors, all seems to be fine.

Could you please advise what need to be corrected in the XML plugin?
Thanks in advance for your support!

https://ww.wp.xz.cn/plugins/google-sitemap-generator/