When using the bottom right corner of a cell to batch copy values across a range by dragging the corner, an error popup appears if a disabled cell is found inside the range that was dragged into.  It is possible to reproduce this with this demo:

https://demos.telerik.com/kendo-ui/spreadsheet/disabled-cells

1.  Set the quantity column to disabled.

2. Select B3.

3.  Drag the bottom right corner of B3 to D3.

4.  See error: "Destination range contains disabled cells."

There should be an option to allow that to copy into any enabled cells in that range and ignore the disabled ones.