Hello everyone,
Recently I started to learn Blender and everything was fine until I tried to export my custom skeleton to UE4. I described an issue below:
Any help will be greatly appreciated. 
What’s the issue? If it is the extra bones untick leaf bones in the exporter. Also you shouldn’t use dots in names because they get converted to underscores in Blender.
Hello Cyaoeu, thanks for your reply. For now leaf bones are not important (or so it seems) and names are the default ones. The problem lies in the hierarchy and its representation in the corresponding programs. I probably just don’t get it entirely yet or do something wrong. In Maya and Blender both skeletons look the same - there’s a “spine” and both “shoulders”, lets call them like that for now. I want shoulders to be parented to spine and look like in images 1, 2 and 3, yet after importing Blender skeleton, like you can see in the image no. 4, the hierarchy looks like “moved” one bone backwards. In that particular image I moved one shoulder from another in UE4, to show that skeleton representation in the editor is different than in Blender - shoulders are parented to the beginning of the spine bone, which is lower, not to the end of the bone, which should be in the middle. I’m very confused by all of this, so sorry if my explanation is unclear.
I don’t really understand the problem, but I know that rigs/skeletons look different in Blender and UE4. The UE4 way never made much sense to me.