Removed alerts

src/editor/js/components/historynavigator.tsx

@@ -22,18 +22,14 @@ export class HistoryNavigator extends React.Component<propTypes> {
      * Undo a step in the history object.
      */
     handleUndo() {
-        if (!this.props.historyObject.undo()) {
-            alert("Something went wrong, could not undo.");
-        }
+        this.props.historyObject.undo();
     }
 
     /**
      * Redo a step in the hisory object.
      */
     handleRedo() {
-        if (!this.props.historyObject.redo()) {
-            alert("Something went wrong, could not redo.");
-        }
+        this.props.historyObject.redo();
     }
 
     /**