Unable to set custom skin for dhtmlxWindows

I used custom skin called [modern_blue] with v2.1.

Upgrade to v3.0, I can not render the dhtmlxWindow anymore, instead i get [Uncaught TypeError: Cannot read property ‘hh’ of undefined]. un comment setSkin or using default skins works.

var wm = new dhtmlXWindows();
win = wm.createWindow('input', 30,30,400,400);
wm.setSkin('modern_blue'); <- this give me the error

i have


Do I have to do special thing to make dhtmlxWindows v3 work with custom skin ?

modern skin is not supported in 3.0

There are only 2 skins:

Here is the sample:

Colours of both skins can be customized using Skin Builder: