Try to register DP agent to HANA Server - connection problem

Hello community :-)!

I am quite new to all the SDI topic and I try to register my freshly installed SAP HANA Data Provisioning Agent with the HANA Server for the first time.

I was following the guide available here:

http://help.sap.com/download/multimedia/hana_options_eim/SAP_HANA_EIM_Administration_Guide_en.pdf

So I have the sufficient user rights. I can connect to the HANA, see all the Adapters, but when I click on Register Agent, give a name (in this example agent_dev01) and type in the hostname I  just get as an Error Message the following:

Is this maybe a problem with the 5050 port (as I used the default one?), that it might be blocked or is there any other possibility what could be wrong here?!

I would be grateful for every little help!

Thanks in advance!
Max