Short version

When auto refresh of the Jenkins GUI is enabled prior to starting a 1.6 -> 2.x upgrade, the upgrade wizard closes after a few seconds due to the auto refresh kicking in.

Versions/software used

• Jenkins 1.6:
  docker run -p 8080:8080 -p 50000:50000 -v /Users/bertjan/jenkins/home:/var/jenkins_home jenkins:1.651.3

• Jenkins 2.3:
  docker run -p 8080:8080 -p 50000:50000 -v /Users/bertjan/jenkins/home:/var/jenkins_home jenkins:2.32.3

Reproduction path

• Install Jenkins 1.6
• Stop the 1.6 instance, start a Jenkins 2.3 instance and point it to the same homedir used for the 1.6 instance
• When the Jenkins 2.3 instance boots, don't log in and start the upgrade wizard just yet
• First, make sure that auto refresh is enabled (by clicking "ENABLE AUTO REFRESH" in the top right corner)
• Click 'Upgrade now' to start the upgrade wizard'
• Click 'Continue'. The upgrade starts.
• Wait a bit for the autorefresh to kick in. This closes the upgrade wizard dialog window.

The upgrade does continue (looking at the logs in my terminal) but there's no way of viewing its progress in the GUI.

This doesn't happen when auto refresh isn't enabled.

Additional info

I marked this issue with priority "major" because this can have quite a negative influence on the trust that new 2.x users have in the upgrade. Imagine finally gaining enough courage for taking the step to upgrade your mission-critical installation to 2.x, only to see the upgrade wizard disappear after a few seconds and being completely in the blue whether the upgrade succeeded or failed. I can hear managers shouting "rollback! rollback!" already

I think it would be alright to just disable auto refresh before the upgrade wizard starts. If the user really wants auto refresh, he/she will enable it again after the upgrade.