Urgency : Standard
When a VCD file is present in the project directory or if it is specified in the ISE "Load Simulation File" option, XPower fails to launch from ISE.
This problem only occurs for CoolRunner projects.
Until this is corrected, you can work around this issue by renaming the VCD file in the project directory to something other than <projectname>.vcd. Do NOT specify this simulation file in the ISE XPower process properties. Launch XPower and then load the simulation file after XPower is open.