Hi Anika,
You need to unwire the filterbar from the grid when you modify the datasource and wire(or reassign) it again after the datasource for the grid is modified. Here is an attached sample seems to work fine by unwiring the grid and rewiring it again without any issues. Could you please give more details on this issue to make this much clearer?
Sample :
Grid_Filterbar.zipBest regards,
Haneef