Use Blender 2.7.4 and export everything with ASCII exporter (Animature + Mesh selected). Also set the scale to match Unreal. Also use latest Unreal public version.
yes UE4 does use fbx(it can also use obj), blender has 2 fbx exporters you can choose from (“fbx 6.1 ASCII” or “fbx 7.4 binary”), using the old 6.1 version often fixes issues like the one you have.
also I have no issues getting animations from blender to UE4, the people that say it’s impossible just haven’t got the workflow right yet.
Can’t say for sure, but I was having a really strange problem with a model exported from Blender that just magically went away a few days ago as well. I don’t think it was 4.7.4 that did id, as it went away before I installed that. I was assuming it was some change between Blender 2.74 RC2 and 2.74 final, but haven’t tested that theory. Am just happy it’s working now.