Error in Console

03.06 04:23:19 [Server] WARN at java.lang.Thread.run(Thread.java:744)
03.06 04:23:19 [Server] WARN at com.mythicacraft.voteroulette.listeners.VoteProcessor.run(VoteProcessor.java:51)
03.06 04:23:19 [Server] WARN at com.mythicacraft.voteroulette.Voter.incrementVoteTotals(Voter.java:300)
03.06 04:23:19 [Server] WARN at com.mythicacraft.voteroulette.Voter.getHoursSince(Voter.java:244)
03.06 04:23:19 [Server] WARN at java.text.DateFormat.parse(DateFormat.java:357)
03.06 04:23:19 [Server] WARN java.text.ParseException: Unparseable date: ""
03.06 04:23:19 [Server] INFO Created new player file: "VoteRoulette/data/playerdata/e9b3ee26-32ab-4bd0-a55e-255f5ab4c541.yml".
03.06 04:23:19 [Server] INFO Received vote record -> Vote (from:Minestatus username:jtcook24 address:99.23.171.172 timeStamp:2014-06-03 01:23:04 -0700)