Win10 64bit, i7-5820K, 2xGTX970
Broken: 2.76 e24323e, 2.76b official
Short description of error
I use the IES2Cycles addon to generate node tree for lamps but this addon does not work correctly with the newest Blender build from buildbot. I tried to generate the nodes in the 2.76b Blender and than open it in the buildbot blender but there were some other problems - the intensity of the lamp changed to negative values (black spots in the scene).
Exact steps for others to reproduce the error
1.) Open the file in the buildbot Blender and switch to rendered view - you can see a bright spot on the ceiling but the ceiling should be dark.
2.) Open the file in the 276b official, switch to rendered view and the the lamp shines correctly.
3.) Save the file in the 276b official and open it in the buildbot version. Switch to rendered view and you see a black spot on the ceiling.
4.) Save the file in the buildbot version and open it in the 276b official. Switch to rendered and the whole scene is completely black.