When I attempt to run XPower referencing a file in a directory with spaces in the path, errors similar to the following occur:
"ERROR:Portability:90 - Command line error: Argument "test\top.ncd" has an invalid
extension. The valid extension is ".pcf". If your file name has more than
one "." in it you must explicitly enter the full file name with its extension."
You can resolve this issue by placing the necessary files (.ncd, .pcf, .cxt, .vcd, .xml) into a directory that does not contain spaces.