error in datagrid after save microflow (An error occurred in listener of event 'onRefresh': TypeError: Cannot read property 'getCurrentGridSize' of null)

Someone an idea what this error means and what I can do to solve it?  The functionality works (commit of entity with associated entities in the datagrid), but I sometimes get an ‘An error occurred, contact systemadministrator.’ error after the close page activity in this save microflow. This is accompanied by an error in the console; An error occurred in listener of event 'onRefresh': TypeError: Cannot read property 'getCurrentGridSize' of null. I do not use  ‘onRefresh’ and ‘getCurrentGridSize' myself.