SAP AS server definition not possible

Hello,

We just installed a new sandbox for our future migration to new SAP Manufacturing Suite 15.1.

So we have now NW 7.4 installed, and I installed latest NWDS version (7.3.1.16).

Problem is that I cannot define the SAP AS server in window->preferences... When I put hostname and instance number, nothing happen, not even any error message anywhere, just nothing!

Our instance number is 00, I don't know if this could be the issue... Or if we missed something in the NW configuration. I tried to define another AS, and it's ok, so it's not NWDS related I think.

Anyone having an idea before we open a ticket at SAP ?

Thanks

Regards

Olivier