The generated script references a Tcl variable ($myScript) that is not created in the script.
The top lines of the script look like the following:
#
# set_process_props
#
# This procedure sets properties as requested during script generation (either
# all of the properties, or only those modified from their defaults).
#
puts "$myScript: setting process properties..."
The "$myScript:" can be removed from the line shown to make the script run correctly.
This problem has been fixed in the latest 10.1 Service Pack available at:
http://www.xilinx.com/support/download/index.htm
The first service pack containing the fix is 10.1 Service Pack 2.