EDIT: The problem is not only about command blocks. No changes save to the map at all!
Some command blocks randomly reset to their state before I edited them when I reload the world. Even though the changes seemingly apply (I even double-check by looking into the command block after editing it) they sometimes randomly switch back. A really frustrating bug for a map maker.
Linked issues
duplicates 1
Attachments
Comments 9
Crash report looks sane.
Can you please attach screenshots or even make a new test world and ZIP or 7Z it and attach it here ?
I attached the affected world. I removed most of the map because I don't want it to be released to the public, but the problem stayed and it's actually much more serious than I thought - no changes made to the world save when I quit it! Enter the world, do something (place any block), save and quit, and then reload the world. No changes will be saved (falling villagers is just me lazy not deleting entities in MCEdit). This never happened to me on any other world. The villagers are NBT-edited and map was MCEdited but that isn't the problem because I have other maps also edited like this and this issue never happened, and edited entities work just fine in vanilla Minecraft. Moreover, nbtediting is now possible with just vanilla minecraft due to /summon command.
That world is broken. You may try to let it repair it via http://www.minecraftforum.net/topic/137381-official-corrupted-save-recovery-thread/
[14:16:25 INFO]: Client> [14:16:25] [Server thread/INFO]: Saving chunks for level 'Bugworld'/Overworld
[14:16:25 INFO]: Client> s: Saving entity NBT
[14:16:25 INFO]: Client> at qn.e(SourceFile:1043)
[14:16:25 INFO]: Client> at qn.d(SourceFile:1010)
[14:16:25 INFO]: Client> at aow.a(SourceFile:209)
[14:16:25 INFO]: Client> at aow.a(SourceFile:96)
[14:16:25 INFO]: Client> at mi.b(SourceFile:146)
[14:16:25 INFO]: Client> at mi.a(SourceFile:175)
[14:16:25 INFO]: Client> at mj.a(SourceFile:604)
[14:16:25 INFO]: Client> at net.minecraft.server.MinecraftServer.a(SourceFile:277)
[14:16:25 INFO]: Client> at bsk.t(SourceFile:113)
[14:16:25 INFO]: Client> at net.minecraft.server.MinecraftServer.run(SourceFile:358)
[14:16:25 INFO]: Client> at ky.run(SourceFile:617)
[14:16:25 INFO]: Client> Caused by: java.lang.NullPointerException
[14:16:25 INFO]: Client> at aez.i(SourceFile:106)
[14:16:25 INFO]: Client> at afa.a(SourceFile:123)
[14:16:25 INFO]: Client> at xh.b(SourceFile:166)
[14:16:25 INFO]: Client> at qn.e(SourceFile:1031)
[14:16:25 INFO]: Client> ... 10 more
[14:16:25 INFO]: Client> s: Saving entity NBT
[14:16:25 INFO]: Client> at qn.e(SourceFile:1043)
[14:16:25 INFO]: Client> at qn.d(SourceFile:1010)
[14:16:25 INFO]: Client> at aow.a(SourceFile:209)
[14:16:25 INFO]: Client> at aow.a(SourceFile:96)
[14:16:25 INFO]: Client> at mi.b(SourceFile:146)
[14:16:25 INFO]: Client> at mi.a(SourceFile:175)
[14:16:25 INFO]: Client> at mj.a(SourceFile:604)
[14:16:25 INFO]: Client> at net.minecraft.server.MinecraftServer.a(SourceFile:277)
[14:16:25 INFO]: Client> at bsk.t(SourceFile:113)
[14:16:25 INFO]: Client> at net.minecraft.server.MinecraftServer.run(SourceFile:358)
[14:16:25 INFO]: Client> at ky.run(SourceFile:617)
[14:16:25 INFO]: Client> Caused by: java.lang.NullPointerException
[14:16:25 INFO]: Client> at aez.i(SourceFile:106)
[14:16:25 INFO]: Client> at afa.a(SourceFile:123)
[14:16:25 INFO]: Client> at xh.b(SourceFile:166)
[14:16:25 INFO]: Client> at qn.e(SourceFile:1031)
[14:16:25 INFO]: Client> ... 10 more
[14:16:25 INFO]: Client> s: Saving entity NBT
[14:16:25 INFO]: Client> at qn.e(SourceFile:1043)
[14:16:25 INFO]: Client> at qn.d(SourceFile:1010)
[14:16:25 INFO]: Client> at aow.a(SourceFile:209)
[14:16:25 INFO]: Client> at aow.a(SourceFile:96)
[14:16:25 INFO]: Client> at mi.b(SourceFile:146)
[14:16:25 INFO]: Client> at mi.a(SourceFile:175)
[14:16:25 INFO]: Client> at mj.a(SourceFile:604)
[14:16:25 INFO]: Client> at net.minecraft.server.MinecraftServer.a(SourceFile:277)
[14:16:25 INFO]: Client> at bsk.t(SourceFile:113)
[14:16:25 INFO]: Client> at net.minecraft.server.MinecraftServer.run(SourceFile:358)
[14:16:25 INFO]: Client> at ky.run(SourceFile:617)
[14:16:25 INFO]: Client> Caused by: java.lang.NullPointerException
etc. etc.OK, I think I know the issue. Some NBT tags used in villagers that worked fine in 1.6 now are invalid in 1.7 (game crashes on trade item mouseover). Well thanks Mojang for breaking a lot of people's maps again, but anyway the issue that was marked a duplicate of this one probably isn't a duplicate because he seems to have vanilla map with no such NBT screwing around. World saving now works fine when I deleted villagers.
The console messages of MC-36328 are the same as here, therefore duplicate.
I found the issue.
Villagers were trading piston heads, whose item versions were removed in 1.7, which somehow caused chunk in which they were present not to save changes upon exiting the game. I resolved the problem by changing their items.
Please force a crash by pressing F3 + C for 10 seconds while in-game and attach the crash report (
[minecraft|http://hopper.minecraft.net/help/finding-minecraft-data-folder]/crash-reports/crash-<DATE>-client.txt) here.