Illegal character in path

I’m using the Flash Builder plugin for eclipse, which has been working fine. When I tried to build my latest project I get an error:

Illegal character in path at index 47: file:///////fp01-pr-whi/Users$/b.gannaway/Flash Builder/ServiceTest/bin-debug/ServiceTest.html

Is this something to do with UNIX/Mac file paths? Has anyone seen this before?