WARNING: Falling back to Push Jobs v1 mode

I am executing a push job and see:
WARNING: Falling back to Push Jobs v1 mode.

Why is it falling back to Push Jobs v1 mode? I suspect this is the reason why the --capture option that i specify during push job start is not working for me because --capture works on version 2.0.

D:\learn-chef\chef-repo>chef -v
Chef Development Kit Version: 0.13.21
chef-client version: 12.9.41
berks version: 4.3.2
kitchen version: 1.7.3

D:\learn-chef\chef-repo>knife -v
Chef: 12.9.41

You’ll see the falling back to v1 mode message when you’ve got a push jobs v1 server installed.

We’ve not done a release of version 2 of the server yet, but it ought to happen in the next week or two I believe.