SinglePlayer Bug

Thank you for your report.
However, your ticket has been resolved as incomplete.

We are unable to diagnose your issue due to the lack of proper debug information. Please review the guidelines before reporting issues.
In case of a game crash, please also attach the crash log from [minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/finding-minecraft-data-folder].

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Minecraft Crash Report ----
// There are four lights!

Time: 15:27 15/11/15
Description: Exception in server tick loop

java.lang.OutOfMemoryError: Java heap space
at anj.a(SourceFile:184)
at anj.a(SourceFile:95)
at ld.b(SourceFile:160)
at ld.a(SourceFile:204)
at le.a(SourceFile:763)
at net.minecraft.server.MinecraftServer.a(SourceFile:364)
at bpo.A(IntegratedServer.java:236)
at net.minecraft.server.MinecraftServer.run(SourceFile:451)
at java.lang.Thread.run(Thread.java:745)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– System Details –
Details:
Minecraft Version: 1.8.8
Operating System: Windows 7 (amd64) version 6.1
CPU: 4x Intel(R) Core(TM) i5-3470 CPU @ 3.20GHz
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 40 bytes (0 MB) / 1060372480 bytes (1011 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 1, tcache: 1, allocated: 12, tallocated: 94
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [lf['noammiz007'/162614, l='Buildings', x=-75.97, y=74.00, z=282.52]]
Type: Integrated Server (map_client.txt)
Is Modded: Very likely; Jar signature invalidated

Invalid. This is a modded client.

Is Modded: Very likely; Jar signature invalidated

hmm. what?