i have manged to add interfaces on vSRX 15.1 D50.3......
But am now not able to use more than one interfaces....like they are visible.. but not operational..they are up/up but do not respond/find arp's..of any interfaces including E1000 E1000E VMXNET2/3.....
this means that no ping is working..... 
Even after adding arp's statically it is not pinging...looks like some issue of L2 (ARP) in these VSRX images....
Atleast juniper should focus more on VSRX image quality..rather than high volume of VMXNET interfaces..whihc has rendered this vSRX totally unusable....
Moreover, in KVM interfaces are also not showing...
Please has anyone managed to solve this issue?
Regards.