Mysterious checkstyle failures are sometimes fixed by reinstalling the plugin

Occasionally students have run into an "Unable to create listeners: formatters" error from checkstyle run in a Gradle task in Android Studio. I haven't yet figured out what actually causes it, but I have noticed that uninstalling and reinstalling the CheckStyle-IDEA plugin has fixed the problem for some people. It's also possible for Gradle to use checkstyle without having the IDE plugin installed - the task can still use checkstyle results, but the warnings won't be displayed in the code editor window.