Property 'grid_scale_date' of object #<Object> is not a func

My app looks like below:

When the tree node in area A is selected, the grid D in the tab B and another grid(not shown in the pic) in the tab C are refreshed, and a row in D is selected, which refreshes the scheduler E.
The problem is:
if the the view in the scheduler is month, week or day, then I swich to the tab C, the grid in C could display correctly. However, if the view in the scheduler is grid, when I switch to the tab C, there’s an error, as below:

Is it a bug or something wrong with my code?