Cannot create a virtual machine inside a virtual network

Hello,

I am unable to create a virtual machine inside a virtual network.

If I try to create the virtual machine without virtual network its OK.

I tried server operation systems (2008 R2, 2012. 2012 R2) and every time the same problem.

In the error message I get "Please try again. If the problem persists, contact support."

Thank you for the help

kobi