Jenkins slaves failing with java.lang.IllegalStateException: Already Connected

[Sean Last]

We're getting this:  <===[JENKINS REMOTING CAPACITY]===>ERROR: Unexpected error in launching a slave. This is probably a bug in Jenkins. java.lang.IllegalStateException: Already connected

I've found this bug, which is still open:  https://issues.jenkins-ci.org/browse/JENKINS-14332

Our master is on 1.596.2, 3.13.0-46-generic for the kernel.

Am I facing this bug, or something else?  Not all our slaves are having this issue, only some of them.

Help, please?

Thanks!

[Sean Last]

So, I've determined that I can still connect to the slave from another master with no issues.  So the issue must be with the master.  

The other master is the exact same kernel and jenkins version.