The renaming commit from a week ago missed the .mcmeta files. The result is that these machines show a purple and black texture when the machines are on.

this fixed it for me

Rename assets/enderio/textures/blocks/
alloySmelterFrontOn.png.mcmeta -> block_alloy_smelter_front_on.png.mcmeta
stirlingGenFrontOn.png.mcmeta -> block_stirling_gen_front_on.png.mcmeta
painterFrontOn.png.mcmeta -> block_painter_front_on.png.mcmeta

ah, right it just occured to me what i forgot to do :D
will fix asap

commit #52 fixed it