Blender EEVEE render engine not working The material shader is not showing or not able to change. Only blank black shader is visible. blender 2.8 test release.
Blender 2.8 is still under development and until the official release is made there are many things that will not work correctly.

Information about reporting bugs in Blender can be found here:
https://wiki.blender.org/index.php/Dev:Doc/Process/Bug_Reports