Selenium Plugin on Jenkins fails to start slaves

[Astou Sene]

Hello! I recently upgraded my Jenkins version to 1.639 and since then, the Selenium plugin has not been able to start the slaves. When I click start on the Node Matching Configuration page, nothing happens. When go on the slave and manually run the command to connect to the master on Jenkins, it works. My Jenkins is on a Linux server and the slaves are Windows machines.

To rule out firewall issue, I opened the ports needed for the communication between Selenium master and slaves to work, that is 4444 on the Jenkins instance and 5555 on the slaves. Are there any intermediate ports I am unaware of?

Could it be related to this issue https://issues.jenkins-ci.org/browse/JENKINS-25583? Is anybody aware of a fix for it?

Anybody else facing this issue?

Your help will be very much appreciated!

Thank you!

Astou Sene