AJAX error when viewing contact groups
I have tested the above issue against WP 4.6.1 and CiviCRM 4.7.11.   I am running Apache 2.4, php 5.6 and MySQL 5.6.   The OS is CentOS 6.

I cannot reproduce this error nor the one mentioned Ajax Error when trying to view relationships tab

I commented in https://issues.civicrm.org/jira/browse/CRM-19331 about this as well.

I would suspect the issue here is due to either a plugin conflict or something specific to the Hosting Configuration. I am interested if these issues are specific to a host or a specific configuration.

I'd disable all plugins (except CiviCRM) and see if you can trace errors in you apache and php logs.  I would also revert to a default theme (CiviCRM demo sites are tested with TwentyThirteen) I'd also look at the CiviCRM logs. The CiviCRM logins should be in the /civicrm/ConfigAndLog directory that is stored in the WP upload directory in 4.7

I'd be interested if these issues are specific to a host or a specific configuration.