Investigate the 'Year' grouping functionality in the angular data table source code. Look for the button's event handler and check if there is a regression or missing implementation. The issue lacks details, so reproducing the problem with the live example at http://swimlane.github.io/angular data table/ may be necessary. Check the grouping logic in files like src/DataTable.js or related modules.
Rowing Group (button) don't work · swimlane/angular-data-table#212 | Good First Issue