as my reply to your answer couldn't be transmitted (don't know why), please find my feedback including taken actions below:
First of all, thanks for your quick answer.
I have downloaded the sling player (version 22.214.171.1242) and the recommended zip-file Telekom MR-303.zip with the 2 bin files V2010_PL and V2010_RV, which I have copied into the folder
C:\Program Files (x86)\Sling Media\SlingPlayer\SBAV.
When starting the setup assistent of the sling player, I receive the message, that this device is not supported by the setup assistant and I'm requested to go to http://support.slingmedia.com/get/suppported-slingplayer-versions. This page returns an Error 404 "page not found". The system assistant is then aborted.
If I choose "connect" from the sling player menu I find (My slingbox - not configured). Doubleclicking on "my slingbox" I get the message that this device is not supported by slingplayer. The request to click the link to the list of supported devices end with a 404 Error "page not found".
Trying to finisht the setup via TV and the slingbox RC using "Other" as device and "V2010" also didn't help.
What's wrong and what else can I do?
Many thanks in advance and