That should help as it indicates where in the java code the failure is occurring. It appears to be something to do with trying to locate your home directory to look for configuration information.
Just a thought - you do not have any none-ASCII characters in your windows username in case that is not being handled correctly, or are running a none-English variant of windows? If you issue the command
Echo %appdata%
in a command window that should tell us where your home folder is located. If that command fails for any reason then simply use the "set" command with no parameters - it would give a lot more output but the information requested should be amongst it somewhere.
Another possibility might be to specify explicitly the folder to hold your calibre2opds configuration information as specified
here in the calibre2opds documentation.