When using the XenApp Plug-in 11.0 or later, SSL Error 59 is displayed when trying to launch an application.
The text of the error is similar to: SSL Error 59: The server sent a security certificate identifying "citrix.domain.com", the SSL connection was to 1.2.3.4. Error number 183.
In the configuration of the Web Interface site, the parameters SSLCommonName and SSLProxyHost might have been configured or the SSLProxyHost parameter might have been defined as an IP Address.

The observed behavior is by design. The XenApp Plug-in verifies that the SSLCommonName and SSLProxyHost, contained in the launch.ica file delivered to the client device, are valid and are part of the same domain.
If the SSLProxyHost parameter is defined as an IP address, the domain name verification against the SSLCommonName will not be successful.

For example:

SSLProxyHost=ag1.company.com & SSLCommonName=ags.company.com are within the same domain.

SSLProxyHost=10.0.0.1 and SSLCommonName=ags.company.com does not work, because no domain name is specified for the SSLProxy Host and cannot be verified against the SSLCommonName.

Problem Cause

If the value of SSLProxyHost is not identical to that of the server name as it appears on the SSL certificate, the SSLCommonName parameter is required, and its value must specify the server name as it appears on the SSL certificate.

These values are contained in the ICA file used to launch the connection – often administrators might set these values in the Override ICA Files on the Web Interface server (for example: default.ica, bandwidth_high.ica, bandwidth_low.ica, and so on). 

Citrix Discussions - Cannot connect to the Citrix XenApp server. SSL Error 59