Thanks a lot!
Will check if I get to that stage back ever. I say other entries in that forum talking about this hence I checked in the dashboard settings. This DLNA Streaming was off. However I was not sure anymore if I uploaded the iphoto library and changed the DLNA setting afterwards.
Hence I wanted to delete this one large file on the EX2 (the first file ever after installation) and upload again with DLNA switched off.
However I have now large problems deleting the file (probably driven by the fact the EX2 is still indexing at 99% CPU Power). I tried on the WD my cloud app and within Finder (both apporaches failed at some point)
and a second problem arised - than at the moment I can not even reach the EX2 through the Dasboard… http://10.0.1.24 Page not found
Thanks again and if you know how I shall best proceed - you are welcome