world crashes when opening world in singleplayer

Thank you for your report!
However, this issue has been temporarily closed as Awaiting Response.

We do not have enough information to find the cause of this issue.
Please attach the crash report (.minecraft/crash-reports/crash-<DATE>-client.txt) here.

If no crash report was created, please attach the launcher log (.minecraft/launcher_log.txt) here.

Once attached, the report will be reopened automatically.

Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki

Minecraft Crash Report ----
// Quite honestly, I wouldn't worry myself about that.

Time: 8/12/18 1:55 AM
Description: Exception in server tick loop

java.lang.OutOfMemoryError: Java heap space
at java.lang.StringCoding$StringDecoder.decode(StringCoding.java:149)
at java.lang.StringCoding.decode(StringCoding.java:193)
at java.lang.String.<init>(String.java:414)
at java.util.jar.Attributes.read(Attributes.java:418)
at java.util.jar.Manifest.read(Manifest.java:251)
at java.util.jar.Manifest.<init>(Manifest.java:69)
at java.util.jar.JarFile.getManifestFromReference(JarFile.java:194)
at java.util.jar.JarFile.getInputStream(JarFile.java:461)
at sun.misc.URLClassPath$JarLoader$2.getInputStream(URLClassPath.java:940)
at sun.misc.Resource.cachedInputStream(Resource.java:77)
at sun.misc.Resource.getByteBuffer(Resource.java:160)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:454)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at net.minecraft.server.MinecraftServer.run(SourceFile:545)
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: 1.13
Operating System: Windows 8 (amd64) version 6.2
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 16287120 bytes (15 MB) / 268435456 bytes (256 MB) up to 268435456 bytes (256 MB)
JVM Flags: 10 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx1G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=16M -Xmx256M
Profiler Position: N/A (disabled)
Player Count: 0 / 8; []
Data Packs: vanilla
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.