ERROR *** AGENT => Failed to send Prolog

Hello,

can someone told me to what this error is related :

ERROR *** AGENT => Failed to send Prolog <URL using bad/illegal format or missing URL>

---------------------------------------

Starting OCS Inventory NG Agent on Wednesday, September 14, 2016 13:10:05.
AGENT => Running OCS Inventory NG Agent Version 2.1.1.3
AGENT => Using OCS Inventory NG FrameWork Version 2.1.1.3
AGENT => Loading plug-in(s)
    DLL PLUGIN => Searching for Plug-in DLL(s) in folder <C:\Program Files (x86)\OCS Inventory Agentnew\plugins>
    DLL PLUGIN => 0 DLL Plug-in(s) successfully loaded on 0 DLL(s) found
AGENT => Using network connection with Communication Server
    COM PROVIDER => Loading Communication Provider <C:\Program Files (x86)\OCS Inventory Agentnew\ComHTTP.dll>
AGENT => Using Communication Provider <OCS Inventory NG cURL Communication Provider> Version <2.1.1.3>
AGENT => Sending Prolog
    DID_CHECK => Read DeviceID <ERD1-W01315-2016-06-01-09-05-39> and MACs <D4:3D:7E:14:B2:DC> in file <ocsinventory.dat>
    COM SERVER => Initializing cURL library for sendRequest
    COM SERVER => Using cURL without server authentication
    COM SERVER => Disabling cURL proxy support
    COM SERVER => Disabling cURL SSL server validation support
    COM SERVER => Sending HTTP Post request to URL <>
    WARNING *** COM SERVER => Failed to send HTTP Post request <URL using bad/illegal format or missing URL>
    COM SERVER => Cleaning cURL library
ERROR *** AGENT => Failed to send Prolog <URL using bad/illegal format or missing URL>
AGENT => Unloading communication provider
AGENT => Unloading plug-in(s)
AGENT => Execution duration: 00:00:00.