jsTree is registered only for IBasicPersonLayer, but INewCanDoLayer does not extend it, so resources are not picked up. INewCanDoSkin does, and that's the only difference between skin and layer. I suggest making the skin a BBB alias for the layer, as SchoolTool has done in 1.4. After that, the trees are displayed correctly even with schooltool 1.4.0.
jsTree is registered only for IBasicPersonLayer, but INewCanDoLayer does not extend it, so resources are not picked up. INewCanDoSkin does, and that's the only difference between skin and layer. I suggest making the skin a BBB alias for the layer, as SchoolTool has done in 1.4. After that, the trees are displayed correctly even with schooltool 1.4.0.