Attempted to Assign to Readonly Property

URL of experiment: Caves_v000011 [PsychoPy]

Description of the problem: Getting the “TypeError: Attempted to assign to readonly property” message. This error occurs only in javascript online. There is no problem when in python on my computer. I have triple-checked the condition files for blank columns, a cause for the error as found by others on Discourse. The problem seems to be due to another type of mistake (as yet unidentified). I am using a list of boolean variables to control the offset of each of 13 mages after a mouse click. The console shows an error break right at the moment an element in that list is reset (from False to True).

Here is the surrounding chunk of code. The first two lines identify which chest has been clicked. The problem seems to be at the third line which is intended to turn off an image of that chest, i.e., “list_of_chest_stops[chest_no] = true;”. The lines after that turn on an image of a gem in the position of the chest that was clicked, assign points, and clean up a bit. It all works seamlessly in python.

if ((gotValidClick && (no_of_selected_chests < no_of_gems))) {
chest_no = util.index(list_of_chest_images, chest_selection.clicked_name[0]);
list_of_chest_stops[chest_no] = true;
list_of_gem_positions[no_of_selected_chests] = list_of_chest_positions[chest_no];
chest_selection.clicked_name = ;
list_of_gem_starts[no_of_selected_chests] = true;
point_total = (point_total + list_of_points[no_of_selected_chests]);
no_of_selected_chests = (no_of_selected_chests + 1);
gem_stop_time = (t + 2);
gotValidClick = false;


And Happy New Year!