NPE after editing a compound type and adding a new field

Added a new field (long) named year to copyright- committed and opened a document which has the field. I get a NPE in the field location. After editing/saving the document the document appears to be fine.

An error has occurred, sorry for that.

java.lang.NullPointerException: null
Failed to instantiate plugin 'org.hippoecm.frontend.editor.plugins.field.PropertyFieldPlugin' for id 'home.cluster.cms-static.plugin.servicesLoader.cluster.cms-services.plugin.hippostdEditorFactory.cluster.cms-compare.plugin.viewerPlugin.cluster.default.plugin.copyright.cluster.default.field'.