A few of these have been reported on the Gamemaker Kitchen, from the looks of it YAL is already looking into it!

The fact that this started happening all of sudden suggests that this is yet another format change brought by an IDE update, but I’m yet to look into it. If your project is relatively small, email me a copy as the other samples I have received are pretty big.

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;

I have the same issue and trying this fix still returns the same "expecting a ds_map" error. (on runtime v2024.4.1.202)