I suppose this is a technical question and may also be suitable for SO proper, but since it concerns the election I thought the target audience would be more likely to find it here.
The download link provided by SO is version 1.7 of OpenSTV. This version does not support unicode but the latest version, 2.0, does. The latest version is available from the OpenSTV.org website, and it costs $5.
Full disclosure, I run the OpenSTV project.
It seems that OpenSTV is assuming that the ballot file is ASCII-encoded, but the chosen handle of one of the candidates, NullUserException ఠ_ఠ contains some characters which aren't.
The quick fix is to simply remove the offending characters1 from the ballot file. Change line 5014 from:
Adding or modifying other lines, such as the actual votes, is possible, but sadly, will have no effect on the real world.
You will then be able to welcome our new ASCII-friendly
1By which I do not mean the candidate!