My OCS agent ins't connecting on server

I installed the OCS Server on a Ubuntu 16.04 LTS. Apparently the installation was fine, but I can't connect any agent to the server.

See the agent log:

First try

Starting OCS Inventory NG Agent on Friday, January 27, 2017 10:57:07.
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)
    DLL PLUGIN => Searching for Plug-in DLL(s) in folder <C:\Program Files (x86)\OCS Inventory Agent\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 Agent\ComHTTP.dll>
AGENT => Using Communication Provider <OCS Inventory NG cURL Communication Provider> Version <2.3.0.0>
    AGENT => Sending getLabel request
    COM SERVER => Initializing cURL library for getFile
    COM SERVER => Using cURL without server authentication
    COM SERVER => Disabling cURL proxy support
    COM SERVER => Disabling cURL SSL server validation support
    COM SERVER => Sending fileGet request to URL <http://192.168.11.86/deploy/label>
    COM SERVER => fileGet response received <HTTP Status Code #404>
    COM SERVER => Cleaning cURL library
    AGENT => Failed to retrieve Label <HTTP Status Code #404>
AGENT => Sending Prolog
    DID_CHECK => Read DeviceID <TGAPPSERVER-2017-01-27-08-56-15> and MACs <18:03:73:EA:FF:9E> 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 <http://192.168.11.86>
    COM SERVER => HTTP Post response received <HTTP Status Code #200>
    COM SERVER => Cleaning cURL library
AGENT => Prolog successfully sent
SUPPORT => No support detected, Registration key : N/A
    AGENT => Prolog Frequency set to 10 hour(s)
    AGENT => Inventory on startup option set to  
AGENT => Unloading communication provider
AGENT => Unloading plug-in(s)
AGENT => Execution duration: 00:00:00.

Second try

Starting OCS Inventory NG Agent on Friday, January 27, 2017 10:58:56.
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)
    DLL PLUGIN => Searching for Plug-in DLL(s) in folder <C:\Program Files (x86)\OCS Inventory Agent\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 Agent\ComHTTP.dll>
AGENT => Using Communication Provider <OCS Inventory NG cURL Communication Provider> Version <2.3.0.0>
    AGENT => Sending getLabel request
    COM SERVER => Initializing cURL library for getFile
    COM SERVER => Using cURL without server authentication
    COM SERVER => Disabling cURL proxy support
    COM SERVER => Disabling cURL SSL server validation support
    COM SERVER => Sending fileGet request to URL <http://192.168.11.86/ocsinventory/deploy/label>
    COM SERVER => fileGet response received <HTTP Status Code #500>
    COM SERVER => Cleaning cURL library
    AGENT => Failed to retrieve Label <HTTP Status Code #500>
AGENT => Sending Prolog
    DID_CHECK => Read DeviceID <TGAPPSERVER-2017-01-27-08-56-15> and MACs <18:03:73:EA:FF:9E> 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 <http://192.168.11.86/ocsinventory>
    COM SERVER => HTTP Post response received <HTTP Status Code #500>
    COM SERVER => Cleaning cURL library
ERROR *** AGENT => Failed to send Prolog <HTTP Status Code #500>
AGENT => Unloading communication provider
AGENT => Unloading plug-in(s)
AGENT => Execution duration: 00:00:00.

My config file

[OCS Inventory Agent]
ComProvider=ComHTTP.dll
Debug=1
Local=
NoSoftware=0
HKCU=0
NoTAG=0
IpDisc=
[HTTP]
Server=http://192.168.11.86/ocsinventory
SSL=0
CaBundle=cacert.pem
AuthRequired=0
User=
Pwd=
ProxyType=0
Proxy=
ProxyPort=0
ProxyAuthRequired=0
ProxyUser=
ProxyPwd=
[OCS Inventory Service]
TTO_WAIT=36000
INVENTORY_ON_STARTUP=0
PROLOG_FREQ=10
OLD_PROLOG_FREQ=10