Added open tasks plugin to a job, and did a build:

[TASKS] Scanning workspace files for tasks...
[TASKS] No annotations have been found.
FATAL: There is no previous build for action hudson.plugins.tasks.TasksResultAction@82c23d
java.util.NoSuchElementException: There is no previous build for action hudson.plugins.tasks.TasksResultAction@82c23d
at hudson.plugins.tasks.TasksResultAction.getPreviousResultAction(TasksResultAction.java:74)
at hudson.plugins.cigame.rules.plugins.opentasks.DefaultOpenTasksRule.evaluate(DefaultOpenTasksRule.java:38)
at hudson.plugins.cigame.model.ScoreCard.record(ScoreCard.java:34)
at hudson.plugins.cigame.model.ScoreCard.record(ScoreCard.java:51)
at hudson.plugins.cigame.GamePublisher.perform(GamePublisher.java:45)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:309)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:297)
at hudson.model.Build$RunnerImpl.cleanUp(Build.java:123)
at hudson.model.Run.run(Run.java:808)
at hudson.model.Build.run(Build.java:85)
at hudson.model.ResourceController.execute(ResourceController.java:70)
at hudson.model.Executor.run(Executor.java:82)