Minecraft: 1.7.10
Magneticraft: 0.6.{0,1}-final
VoltzEngine: 0.25.{2.317,4.319}
Crash-report

I know, 1.7.10 is unsupported, but...
Crash rises after add VoltzEngine (MFFS dep).
If use only MFFS or Magneticraft all going fine.

Well, it is false alarm - reinstalled MC and all became fine.
Shame on me :'(