I am trying to copy bone weights (as usual) by shift clicking old and new object, going in weight paint mode and selecting “transfer weights”.
Underneath the transfer button there should be a “tab” panel showing options for source layers and the like, but now there is nothing there, all I can see is “History”.
Using v2.78a, is the TMD tab moved?
Is this what you want https://docs.blender.org/manual/en/dev/modeling/meshes/editing/data_transfer.html
Not exactly but thanks for trying 
This image shows at number “5” what I miss from my viewport tool shelf. (hope the link works)
Sometimes it is hidden at the bottom. Look below history or rigify if you have that on and see if you have this little item.
If so click on it and drag up.
Yeah, you’re so right! I found it by dragging on a tiny grey plus sign at the bottom! I have no idea how it got that way 
Thank you very much
