Failed to send Prolog

Using server 2.1.2 on Windows

Trying to use agent 2.3.0.0

Working fine with an older version tho.

Is the above ment to working even?

Starting OCS Inventory NG Agent on Monday, January 16, 2017 12:38:05.
AGENT => Running OCS Inventory NG Agent Version 2.3.0.0
AGENT => Using OCS Inventory NG FrameWork Version 2.3.0.0
AGENT => Loading plug-in(s)
AGENT => Using network connection with Communication Server
AGENT => Using Communication Provider <OCS Inventory NG cURL Communication Provider> Version <2.3.0.0>
AGENT => Sending Prolog
ERROR *** AGENT => Failed to send Prolog <HTTP Status Code #400>
AGENT => Unloading communication provider
AGENT => Unloading plug-in(s)
AGENT => Execution duration: 00:00:00.