Version: SpongeVanilla version 1.11.2-6.0.0-BETA-251
Just run a new server, and login then happen:
[23:59:52] [Server thread/ERROR] [MinecraftServer]: Encountered an unexpected exception
java.lang.AbstractMethodError: Method net/minecraft/tileentity/TileEntityMobSpawner.getFailedData()Ljava/util/List; is abstract
at net.minecraft.tileentity.TileEntityMobSpawner.getFailedData(SourceFile) ~[asr.class:?]
at net.minecraft.tileentity.TileEntity.writeToNbt(SourceFile:2782) ~[asc.class:?]
at net.minecraft.tileentity.TileEntity.handler$onWriteToNBT$zih001(SourceFile:2697) ~[asc.class:?]
at net.minecraft.tileentity.TileEntity.func_189515_b(SourceFile) ~[asc.class:?]
at net.minecraft.tileentity.TileEntityMobSpawner.func_189515_b(SourceFile:83) ~[asr.class:?]
at net.minecraft.tileentity.TileEntityMobSpawner.func_189517_E_(SourceFile:102) ~[asr.class:?]
at net.minecraft.network.play.server.SPacketChunkData.<init>(SourceFile:52) ~[gw.class:?]
at net.minecraft.server.management.PlayerChunkMapEntry.func_187272_b(SourceFile:106) ~[mb.class:?]
at net.minecraft.server.management.PlayerChunkMap.func_187302_c(SourceFile:202) ~[mc.class:?]
at net.minecraft.server.management.PlayerChunkMap.func_72683_a(SourceFile:227) ~[mc.class:?]
at net.minecraft.server.management.PlayerList.func_72375_a(SourceFile:264) ~[mt.class:?]
at net.minecraft.server.management.PlayerList.handler$playerLoggedIn2$zhg000(SourceFile:1815) ~[mt.class:?]
at net.minecraft.server.management.PlayerList.func_72377_c(SourceFile:305) ~[mt.class:?]
at net.minecraft.server.management.PlayerList.initializeConnectionToPlayer(SourceFile:1317) ~[mt.class:?]
at net.minecraft.server.management.PlayerList.func_72355_a(SourceFile:1173) ~[mt.class:?]
at net.minecraft.server.network.NetHandlerLoginServer.func_147326_c(SourceFile:120) ~[mk.class:?]
at net.minecraft.server.network.NetHandlerLoginServer.func_73660_a(SourceFile:66) ~[mk.class:?]
at net.minecraft.network.NetworkManager.func_74428_b(SourceFile:232) ~[er.class:?]
at net.minecraft.network.NetworkSystem.func_151269_c(SourceFile:187) ~[mh.class:?]
at net.minecraft.server.MinecraftServer.func_71190_q(SourceFile:1603) ~[MinecraftServer.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(SourceFile:335) ~[lh.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(SourceFile:562) ~[MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:466) [MinecraftServer.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_71]
[23:59:52] [Server thread/ERROR] [MinecraftServer]: This crash report has been saved to: ***\crash-reports\crash-2017-04-18_23.59.52-server.txt
[23:59:52] [Server thread/INFO] [MinecraftServer]: Stopping server
[23:59:52] [Server thread/INFO] [MinecraftServer]: Saving players
[23:59:52] [Server thread/ERROR] [MinecraftServer]: Exception stopping the server
java.lang.AbstractMethodError: Method net/minecraft/entity/player/EntityPlayerMP.getFailedData()Ljava/util/List; is abstract
at net.minecraft.entity.player.EntityPlayerMP.getFailedData(SourceFile) ~[ly.class:?]
at net.minecraft.entity.Entity.writeToNbt(SourceFile:5056) ~[sn.class:?]
at net.minecraft.entity.EntityLivingBase.writeToNbt(SourceFile:2549) ~[sw.class:?]
at net.minecraft.entity.Entity.handler$onWriteToNBT$zci000(SourceFile:4953) ~[sn.class:?]
at net.minecraft.entity.Entity.func_189511_e(SourceFile) ~[sn.class:?]
at net.minecraft.world.storage.SaveHandler.func_75753_a(SourceFile:150) ~[bbt.class:?]
at net.minecraft.server.management.PlayerList.func_72391_b(SourceFile:289) ~[mt.class:?]
at net.minecraft.server.management.PlayerList.func_72389_g(SourceFile:738) ~[mt.class:?]
at net.minecraft.server.MinecraftServer.func_71260_j(SourceFile:395) ~[MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:499) [MinecraftServer.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_71]