So the mansion cloud plugin does not pay attention to locking when removing nodes. This can result in builds starting on a node that does not exist or a build being aborted while in progress as it gets removed. This will result in stack traces such as:

java.lang.IllegalStateException: no longer a configured node for 1f13542c
at hudson.model.AbstractBuild$AbstractBuildExecution.getCurrentNode(AbstractBuild.java:462)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:494)
at hudson.model.Run.execute(Run.java:1745)
at hudson.matrix.MatrixRun.run(MatrixRun.java:146)
at hudson.model.ResourceController.execute(ResourceController.java:89)
at hudson.model.Executor.run(Executor.java:240)

For correct behaviour look at some of the recent changes to the durable builds plugin within the retention strategy (or - if you are a bee - the closed source operations-center-cloud or nectar-vmware plugins of CloudBees... though this should just be additional examples of the changes pushed to the durable tasks plugin)