After over 48 hours of downtime on my server ObsidianCraft.com, I have finally found the source of the "Connection Reset" problem... There are corrupt .dat user files which cause vanilla minecraft to hang. Indeed they even cause mcedit to hang with errors like "invalid block length." Is there a tool to check the integrity of player data files? I have over 100,000 of them, and I do not want to simply delete them. I have cleared old player file by using a list of inactive player I had in SQL, but that did not help. Note: If there are no existing tools and someone can make a tool to do this and it works, I will pay up to $150 if delivered soon. (PM me if you can help) Thanks!