World gen error, while mining

10.10 02:58:16 [Server] SEVERE at net.minecraft.server.dedicated.DedicatedServerListenThread.func_71747_b(DedicatedServerListenThread.java:34)
10.10 02:58:16 [Server] SEVERE at net.minecraft.network.NetworkListenThread.func_71747_b(NetworkListenThread.java:54)
10.10 02:58:16 [Server] SEVERE at net.minecraft.network.NetServerHandler.func_72570_d(NetServerHandler.java:231)
10.10 02:58:16 [Server] SEVERE at net.minecraft.network.TcpConnection.func_74428_b(TcpConnection.java:468)
10.10 02:58:16 [Server] SEVERE at net.minecraft.network.packet.Packet14BlockDig.func_73279_a(Packet14BlockDig.java:67)
10.10 02:58:16 [Server] SEVERE at net.minecraft.network.NetServerHandler.func_72510_a(NetServerHandler.java:767)
10.10 02:58:16 [Server] SEVERE at net.minecraft.item.ItemInWorldManager.func_73082_a(ItemInWorldManager.java:296)
10.10 02:58:16 [Server] SEVERE at net.minecraft.item.ItemInWorldManager.func_73084_b(ItemInWorldManager.java:468)
10.10 02:58:16 [Server] SEVERE at net.minecraft.item.ItemInWorldManager.func_73079_d(ItemInWorldManager.java:340)
10.10 02:58:16 [Server] SEVERE at net.minecraft.block.Block.removeBlockByPlayer(Block.java:1704)
10.10 02:58:16 [Server] SEVERE at net.minecraft.world.World.func_94571_i(World.java:1031)
10.10 02:58:16 [Server] SEVERE at net.minecraft.world.World.func_72832_d(World.java:839)
10.10 02:58:16 [Server] SEVERE at net.minecraft.world.chunk.Chunk.func_76592_a(Chunk.java:727)
10.10 02:58:16 [Server] SEVERE at BlockTimberTree.func_71852_a(BlockTimberTree.java:20)
10.10 02:58:16 [Server] SEVERE java.lang.NoSuchMethodError: net.minecraft.src.ModLoader.getMinecraftInstance()Lnet/minecraft/client/Minecraft;
10.10 02:58:11 [Server] INFO list