Wrong Gateway! Server error - what's wrong here?

Look here: https://aw-snap.info/file-viewer/?tgt=https%3A%2F%2Fhaos.hopto.org%2Fdotnet%2F&ref_sel=GSP2&ua_sel=ff&fs=1
and here: http://toolbar.netcraft.com/site_report?url=https://haos.hopto.org

Some issues with WordPress plug-ins: WordPress Plugins
The following plugins were detected by reading the HTML source of the WordPress sites front page.

all-in-one-seo-pack 2.3.11.2 latest release (2.3.11.2)
https://semperfiwebdesign.com
captcha 4.2.8 latest release (4.2.8)
http://bestwebsoft.com/products/wordpress/plugins/captcha/
syntaxhighlighter latest release (3.2.1)
http://www.viper007bond.com/wordpress-plugins/syntaxhighlighter/
cookie-law-info 1.5.3 latest release (1.5.3)
http://wordpress.org/extend/plugins/cookie-law-info/description/
wp-lightbox-2 latest release (3.0.6.2)
http://wpdevart.com/wordpress-lightbox-plugin
Plugins are a source of many security vulnerabilities within WordPress installations, always keep them updated to the latest version available and check the developers plugin page for information about security related updates and fixes.

Warning User Enumeration is possible
The first two user ID’s were tested to determine if user enumeration is possible.

ID User Login
1 None admin
2 None
It is recommended to rename the admin user account to reduce the chance of brute force attacks occurring. As this will reduce the chance of automated password attackers gaining access. However it is important to understand that if the author archives are enabled it is usually possible to enumerate all users within a WordPress installation.

Warning Directory Indexing Enabled
In the test we attempted to list the directory contents of the uploads and plugins folders to determine if Directory Indexing is enabled. This is an information leakage vulnerability that can reveal sensitive information regarding your site configuration or content.

/wp-content/uploads/ enabled
/wp-content/plugins/ disabled
Directory indexing was tested on the /wp-content/uploads/ and /wp-content/plugins/ directores. Note that other directories may have this web server feature enabled, so ensure you check other folders in your installation. It is good practice to ensure directory indexing is disabled for your full WordPress installation either through the web server configuration or .htaccess.

Firehol blocked this with a level/1 block: -http://89-76-67-245.dynamic.chello.pl/ = Reverse DNS address.

B-status: https://sritest.io/#report/277a41f7-4ad8-4a82-9e4f-0179d885e475

Vuln: -/haos.hopto.org/blog/wp-includes/js/jquery/jquery.js?ver=1.12.4

F-F-F-X status: https://observatory.mozilla.org/analyze.html?host=haos.hopto.org

polonus (volunteer website security analyst and website error-hunter)

Here we see there was a recent zone-transfer: http://www.dnsinspect.com/hopto.org/10002172
And also consider this: http://www.domxssscanner.com/scan?url=https%3A%2F%2Fhaos.hopto.org%2Fblog%2F
Grade-C status: https://www.htbridge.com/websec/?id=6f8c330b8db72bf1646c4b1ba7f6aa46a130447b37ce933f113c54a0a8d6d2f7
The certificate is untrusted, users may not be able to access the website because HSTS forbids bypass of the browser error message - You have 1 error
Wrong certificate installed.
The domain name does not match the certificate common name or SAN. Host: -sales.upc-cablecom.ch

polonus