Are you obliged in this situation to signal parking of the damaged agricultural tractor?

The visible D-42 "Grodztwo" sign indicates entry into a built-up area. According to regulations, in such an area, a vehicle stoppage caused by a breakdown must be signalled if it takes place in a location where stopping is prohibited. Stopping a vehicle in a traffic lane is prohibited, therefore the driver of the tractor is required to signal the stoppage appropriately.