Ah, you have, I guess, made the arms or torso longer than the original shape - to fix that you need to go to Edit>Figure>Rigging>Adjust rigging to shape, then (assuming that works) zero the pose so that the only changes to the base figure are the new rigging and your morph. Now you need to go to the Proeprty editor pane menu - if you have to open the pane it will take ages to populate, but you don't actually need ti - just the tab - so if you have it docked in a group and behind another pane just right-click the tab and pick ERC Freeze...; make sure that Figure iss et to your figure, the node to the node that has the morph (Genesis), and the Property to your morph, and that all of the changed joints are seelcted in the Freeze properties list, and that the check boxes at the bottom are all selected. After applying that, you should find that your morph adjusts the joint centres so that the figure still poses correctly - assuming you are happy with the result, File>Save as>Support Asset(s)>Morph Asset and you're done.