Well...I can't really what happened, just loaded my game and, it seems like, BuildCraft crashed by itself
https://docs.google.com/document/d/1WBrNEXg6u-fg0PhEE4o9ORu2bK_Kibf0i_PBgdRvzjk/edit?usp=sharing
(File was too heavy for pastebin)

One of your mods is bundling an outdated version of the BuildCraft API (pre-6.1.5).