itch.io

A further inspection reveals that it’s not been caused by a format change itself, but forgotten code from adjusting the format. You’ll want to find the following in GMLive script:

	var l_lrs = ds_map_find_value(l_rm, "layers");
	var l_lrk = ds_list_size(l_lrs);
	for (var l_lri = 0, l__g1 = ds_list_size(l_lrs); l_lri < l__g1; l_lri++) {
		live_room_loader_add_layer(ds_list_find_value(l_lrs, l_lrk));
	}

and replace it with

	var l_lrs = ds_map_find_value(l_rm, "layers");
	for (var l_lri = 0, l__g1 = ds_list_size(l_lrs); l_lri < l__g1; l_lri++) {
		live_room_loader_add_layer(ds_list_find_value(l_lrs, l_lri)); // <- lri instead of lrk
	}

Edit: and also find this

var l_ql_sublayer_count = ds_list_size(l_ql_sublayers);

and replace it with

var l_ql_sublayer_count = l_ql_sublayers != undefined && l_ql_sublayers != pointer_null ? ds_list_size(l_ql_sublayers) : 0;