Cannot create test instance

Hi,

I'm stuck right from the start. I created a HANA trial account and try to follow the guidance in "Creating an SAP HANA XS application". The first step is to create a HANA test instance. Doesn't work, the server notifies me that it can't create a certificate :

Maybe I'm missing something but I don't find any hints in the existing threads.

Any help gladly appreciated,

Michael