I had to revisit some deployments I created recently to modify some content locations. On any deployment that had both AutoCAD and an AutoCAD based vertical package (ACA or MEP), the deployment modification routine would hang when I tried to modify either the ACA or AMEP product if I had modified the support paths in the AutoCAD versions (AutoCAD or Struc Designer) first.
I was able to restore the paths to default by modding the AMEP, then ACA, then Struc designer, then AutoCAD. If you run into this, try modding the paths in the above order.