When I try to compile the SPI-42 Core simulation file generated from NetGen, the following error occurs:
"#**.vhd (#n): (vcom-1136) Unknown identifier "msgon""
This error occurs because NetGen does not output "msgon" for SimPrim libraries. This is a problem with all simulations that use components that have "msgon" attributes.
This issue is fixed in ISE 9.1i Service Pack 2, which is scheduled for release in early 2007.