I have imported a bunch of map data from OpenStreetMap, most of which has been converted to appropriate orienteering symbols, but some objects, like picnic tables have not been converted and are simply purple points. I would like to convert these to man-made objects, but OOM is not allowing me to do so. When I select the object and then right-click on the prominent man-made object symbol the option to Switch symbol of selected objects is greyed out. The same happens when I try to convert any point symbol to any other point symbol. Am I doing something wrong? Screen capture of the problem is found below.

I have imported a bunch of map data from OpenStreetMap, most of which has been converted to appropriate orienteering symbols, but some objects, like picnic tables have not been converted and are simply purple points. I would like to convert these to man-made objects, but OOM is not allowing me to do so. When I select the object and then right-click on the prominent man-made object symbol the option to
Switch symbol of selected objectsis greyed out. The same happens when I try to convert any point symbol to any other point symbol. Am I doing something wrong? Screen capture of the problem is found below.