This is a known issue with 13.3 XPS. The problem is with NLView-based Graphical Design View (GDV)introduced in the13.3 release (13.2 works fine).
In somedesigns, port bus LOCKSTEP_SLAVE_IN[0:4095] of the MicroBlaze processor is connected to ground (net_gnd). GDV creates 4096 nets which gets connected to this port bus NLView takes time to create these many nets connected to net_gnd. This can also occur when any large-width signal is in the design.
This issue is to be addressed in the 13.4 design tools release.