The character file under the map name ALWAYS gets corrupted.

Log:
[17:11:11] [Server thread/INFO]: Starting minecraft server version 14w10b
[17:11:11] [Server thread/INFO]: Loading properties
[17:11:11] [Server thread/INFO]: Default game type: SURVIVAL
[17:11:11] [Server thread/INFO]: Generating keypair
[17:11:11] [Server thread/INFO]: Starting Minecraft server on *:25565
[17:11:12] [Server thread/WARN]: Could not lookup user uuid for a20dc880-988f-4ff0-ac58-a6f59d74e649
com.mojang.authlib.yggdrasil.ProfileNotFoundException: Server did not find the requested profile
at com.mojang.authlib.yggdrasil.YggdrasilGameProfileRepository.findProfilesByNames(YggdrasilGameProfileRepository.java:90) [minecraft_server.14w10b.jar:?]
at pe.a(SourceFile:57) [minecraft_server.14w10b.jar:?]
at pe.a(SourceFile:353) [minecraft_server.14w10b.jar:?]
at my.aF(SourceFile:426) [minecraft_server.14w10b.jar:?]
at my.g(SourceFile:145) [minecraft_server.14w10b.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:367) [minecraft_server.14w10b.jar:?]
at mp.run(SourceFile:667) [minecraft_server.14w10b.jar:?]
[17:11:12] [Server thread/ERROR]: Conversion failed, please try again later
pl: Could not convert file for a20dc880-988f-4ff0-ac58-a6f59d74e649
at pk.a(SourceFile:335) ~[minecraft_server.14w10b.jar:?]
at pk.onProfileLookupFailed(SourceFile:324) ~[minecraft_server.14w10b.jar:?]
at com.mojang.authlib.yggdrasil.YggdrasilGameProfileRepository.findProfilesByNames(YggdrasilGameProfileRepository.java:93) ~[minecraft_server.14w10b.jar:?]
at pe.a(SourceFile:57) ~[minecraft_server.14w10b.jar:?]
at pe.a(SourceFile:353) [minecraft_server.14w10b.jar:?]
at my.aF(SourceFile:426) [minecraft_server.14w10b.jar:?]
at my.g(SourceFile:145) [minecraft_server.14w10b.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:367) [minecraft_server.14w10b.jar:?]
at mp.run(SourceFile:667) [minecraft_server.14w10b.jar:?]
[17:11:12] [Server thread/WARN]: **** DETECTED OLD PLAYER DIRECTORY IN THE WORLD SAVE
[17:11:12] [Server thread/WARN]: **** THIS USUALLY HAPPENS WHEN THE AUTOMATIC CONVERSION FAILED IN SOME WAY
[17:11:12] [Server thread/WARN]: ** please restart the server and if the problem persists, remove the directory 'MIKEANDZIKE\players'
[17:11:38] [Server thread/INFO]: Stopping server