If your plugin needs to create files and store data in the filesystem, you should use the getPluginHome() API of the EditPlugin class. To signal that you use the plugin home API you have to set the plugin.class name.usePluginHome property to true. Even if your plugin doesn't create any files, you should set the property to true, so that e. g. the plugin manager knows that there is actually no data in favor of not knowing if there is any data and thus displaying that it doesn't know the data size. See the documentation for the EditPlugin class for details.