Due to the nodes structure changes in the latest Blender 2.81 release, all open materials in the BIS library have been updated for this version of Blender. Compatibility with younger versions of Blender could be lost (depends on the nodes used in the material).
Two new modes were introduced to work separately, one for materials (easier to use) and the second – for node groups (for advanced shader making). In the “Material” mode, the entire material is stored and loaded. In the “NodeGroups” mode, everything works without changes, a separate node group is saved and loaded for the convinient creating complex shaders.
In the “NodeGroup” mode uploaded node group adds to the current open node group instead of the node tree root as before.
Experimental mode can be enabled/disabled in the add-on preferences.
Normal maps are usually saved in one of the two most common formats: OpenGL or DirectX. Blender uses OpenGL specification. Trying to use normal maps saved in another format will result in the wrong visual effect. To convert normal maps to the desired format the “OpenGL – DirectX Normal Map Converter” node group from the BIS material library can be used.