As I see, in 4.2.1 all content of them does not recover after grid view refreshing (for example, after page navigation) - it only recovers text context of rowTpl. So I did following workaround:

  1.     viewBodyExpandEventHandler: function (row, r) {
  2.         if (!row.grid) {
  3.             this.gridCreateRoutine(row, r.get('id'));
  4.         }
  5.     },
  6.     viewRevreshEventHandler: function () {
  7.         // Of course, in init method of my controller this.hashOfGrids = {};
  8.         Ext4.Object.each(this.hashOfGrids, function(id, data) {
  9.             this.createRowGrid(data.el, data.id);  
  10.         }, this);    
  11.     },
  12.     gridCreateRoutine: function(row, id) {
  13.         var l = 'renderdiv' + id,
  14.             el = Ext.fly(layer);
  15.         if (el) {
  16.            el.setHTML('');
  17.            Ext.create('Ext.grid.Panel', {
  18.                 renderTo : l,
  19.             });
  20.             this.hashOfGrids[id] = {
  21.                 el  : row,
  22.                 id  : id        
  23.             };
  24.         }
  25.     },
  26.