ahh yes, not so much a problem as an upgrade.
We removed the action for entity attach because it was awkward and struggled to be expanded.
Instead we added a simpler approach of dragging the entity you want to attach onto the other entity using the drag and drop of the scene entity list.
Of course this also means you can drag entities onto the bones or attach cameras and lights easily.
One known issue is when saving an entity to preset that has more than 1 child depth and will be fixed for next release.
The documentation all needs upgraded at some point
Hope this helps
p.s. if you need more information or what i said doesnt make sense, then i can make an image if necessary.