Error in program SAPLCKDI screen 4610

Hi everyone.

I've have trouble with screen 4610 in program SAPLCKDI, during costing sales order.

In sometimes we have a runtime error in the same program and same screen.

That's the runtime error: Overwriting a protected field

In other cases, the mentioned screen appears with a lot of special characters like #.

The costin lot size field appears with a weird value over than 1 bilion.

Kind regards.