Here is the error I receive when I play my singleplayer world:

java.io.FileNotFoundException: C:\Users\Samuel\Downloads\MultiMC\instances\WipCraft\minecraft\saves\Lets Play WiP No_ 1\players.baub (The system cannot find the path specified)
at java.io.FileOutputStream.open(Native Method)
at java.io.FileOutputStream.(Unknown Source)
at java.io.FileOutputStream.(Unknown Source)
at baubles.common.lib.PlayerHandler.savePlayerBaubles(PlayerHandler.java:143)
at baubles.common.lib.PlayerHandler.loadPlayerBaubles(PlayerHandler.java:98)
at baubles.common.network.EventHandlerNetwork.playerLoggedInEvent(EventHandlerNetwork.java:16)
at cpw.mods.fml.common.eventhandler.ASMEventHandler_107_EventHandlerNetwork_playerLoggedInEvent_PlayerLoggedInEvent.invoke(.dynamic)
at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:51)
at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:122)
at cpw.mods.fml.common.FMLCommonHandler.firePlayerLoggedIn(FMLCommonHandler.java:549)
at net.minecraft.server.management.ServerConfigurationManager.a(ServerConfigurationManager.java:180)
at cpw.mods.fml.common.network.handshake.NetworkDispatcher.completeServerSideConnection(NetworkDispatcher.java:173)
at cpw.mods.fml.common.network.handshake.NetworkDispatcher.completeHandshake(NetworkDispatcher.java:446)
at cpw.mods.fml.common.network.internal.HandshakeCompletionHandler.channelRead0(HandshakeCompletionHandler.java:17)
at cpw.mods.fml.common.network.internal.HandshakeCompletionHandler.channelRead0(HandshakeCompletionHandler.java:11)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:98)
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337)
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111)
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337)
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785)
at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:169)
at cpw.mods.fml.common.network.internal.FMLProxyPacket.func_148833_a(FMLProxyPacket.java:77)
at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:212)
at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:165)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:659)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:111)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

Until Azanor updates baubles to work on 1.7, use my fork. Mind the red text on the thread: http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/2132152-baubles-princess-edition-1-0-0-18p-last-updated-7