Early the week of July 4th 2013 I was working with a customer on a Juniper QFX3000-M Micro Fabric in their lab running through various setup steps while the setup steps where documented on their internal wiki.
When running through the process of a recovery installation on the Director Group an error message appeared stating the ks.cfg (kickstart file) could not be downloaded.
Researching this further showed that there was a ks.cfg file present exactly where it was supposed to be and that the ks.cfg file was populated with 21 thousands bytes of data.
So after several attempts and scratching of the head, it turns out simply hitting the enter key (“OK”) at the error message (below) allowed the process to continue; in our case the process continued to a successful conclusion after this.
If you run across this in the field try hitting the enter key like above, if that doesn’t work then I would pursue opening a JTAC case.
Juniper Networks’s QFabric System
General search on “all about kickstart installation”
The recovery installation on the director group is documented here,
Contacting Juniper Support