The connection test to WordPress fails with a message ‘Unknown error’

Question

What if the connection test to WordPress fails with a message ‘Unknown error’

Answer

One of the causes might be that a plugin that controls or influences access to API’s or user access rights is active. An example is “Jetpack – WP Security, Backup, Speed, & Growth”.

SuperOffice for Wordpress needs explicit access to the user API.

Contact your WordPress administrator or the developer of the plugin for help in configuring the plugin.