-If you are using the correct skeleton, you should not rename any bones. If you did, change them back to their original name. (it should in fact be lhang_tag_bone and not lhand) lhand_ is used for Jedi Academy only.
-Do not assign any vertex weight to that bone.
-Locate the "bolt_l_hand" tag, this tag should not be weighted to lhang_tag_bone, if it is, remove the bone from the list and use the "lhand" bone instead
Try that and see if that fixes the issue.