17:27:38 [SEVERE] Cannot load plugins/iSafe/Users/53773.txt
org.bukkit.configuration.InvalidConfigurationException: unacceptable character '?' (0xFFFD) special characters are not allowed
in "<string>", position 36
        at org.bukkit.configuration.file.YamlConfiguration.loadFromString(YamlConfiguration.java:54)
        at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:138)
        at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:105)
        at org.bukkit.configuration.file.YamlConfiguration.loadConfiguration(YamlConfiguration.java:174)
        at com.mrmag518.iSafe.UserFileCreator.UserString(UserFileCreator.java:50)
        at com.mrmag518.iSafe.UserFileCreator.CreateUserFile(UserFileCreator.java:43)
        at sun.reflect.GeneratedMethodAccessor326.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:459)
        at net.minecraft.server.ServerConfigurationManager.c(ServerConfigurationManager.java:132)
        at net.minecraft.server.NetLoginHandler.b(NetLoginHandler.java:129)
        at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:41)
        at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:61)
        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:567)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:459)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
Caused by: unacceptable character '?' (0xFFFD) special characters are not allowed
in "<string>", position 36
        at org.yaml.snakeyaml.reader.StreamReader.checkPrintable(StreamReader.java:70)
        at org.yaml.snakeyaml.reader.StreamReader.<init>(StreamReader.java:50)
        at org.yaml.snakeyaml.Yaml.load(Yaml.java:399)
        at org.bukkit.configuration.file.YamlConfiguration.loadFromString(YamlConfiguration.java:52)
        ... 18 more