This is driving me mad, the left arm which sits slightly behind my character works fine and hinges from the shoulder. The right arm which is the top layer will not attach to the shoulder no matter what i do. I'm sure its something simple but ive literally spent all afternoon trying different things. The online tutorials mostly show an older version so doesn't completely apply to my problem. I really would be grateful for any assistance, regards, John.
Hard to make a suggestion without more details, but the most common unexpected problem I hear of is the independent arm group should have "Attach To" set to "Auto" in the properties panel (it is often the parent group name by default - which some have said is a bug for independent groups). You can then drag the circle over the torso at the attach point until it goes green indicating correct attachment.
Sorry if you have done all this already. (Your post is almost a week old, so maybe you have sorted it out already.)