Plugin crashes when run on an agent

[Roel van Dijk]

When we use this plugin, labeling works fine as long as we run the plugin on the Bamboo server itself. When the plugin is run on an agent (either Linux or Windows agent), we see the following failure in the log file:

Error generating zip file : null

The error is logged on line 112 of LabelPlanTask. Not sure why it mentions a zip file, probably a copy-pasted line of code?

We suspect that the planManager was not set properly and we get a NullPointerException on line 42 (planManager.getPlanByKey(planKey)), but we haven't tested that.