What does the FileSink module do when when the specified path is not valid? Does it just not created the file?
Also, is there an easy to way to specify a valid path for both Windows and Linux?
Yes you are correct that it does not create the file if the path is invalid.
The most simple way to have a valid path for both Windows and Linux would be to use "./" as the file path. This will place the output file in the same directory as the executable. So for Windows it would be placed in the "Bin\win32-vc100-rel" folder (where AWE_Server.exe) lives, and on Linux it would be placed wherever the application lives.
Hope this helps!