If it is of any help I apparently "crashed" when I entered the portal and this report was created. It's thanks to a mod that shows when something wrong occurs during the game, VanillaFix I think.
It seems something went wrong with PlayerAdvancement....?
(I had to crop the report)
---- Minecraft Crash Report ----
// This doesn't make any sense!
Time: 2020-05-26 17:59:24 EEST
Description: Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at net.minecraft.util.Util.runTask(Util.java:531)
at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:273)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at net.minecraft.advancements.PlayerAdvancements.setSelectedTab(PlayerAdvancements.java:360)
at net.minecraft.network.NetHandlerPlayServer.handleSeenAdvancements(NetHandlerPlayServer.java:447)
at net.minecraft.network.play.client.CPacketSeenAdvancements.processPacket(SourceFile:50)
at net.minecraft.network.play.client.CPacketSeenAdvancements.processPacket(SourceFile:11)
at net.minecraft.network.PacketThreadUtil$1.run(PacketThreadUtil.java:22)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at net.minecraft.util.Util.runTask(Util.java:529)
... 3 more
A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------
-- System Details --
Minecraft Version: 1.12.2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 980828888 bytes (935 MB) / 6210977792 bytes (5923 MB) up to 6210977792 bytes (5923 MB)
JVM Flags: 26 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmn768m -Xmx6000M -Xms6000M -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+UseNUMA -XX:+CMSParallelRemarkEnabled -XX:MaxTenuringThreshold=15 -XX:MaxGCPauseMillis=30 -XX:GCPauseIntervalMillis=150 -XX:+UseAdaptiveGCBoundary -XX:-UseGCOverheadLimit -XX:+UseBiasedLocking -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -XX:MaxTenuringThreshold=15 -XX:+UseFastAccessorMethods -XX:+UseCompressedOops -XX:+OptimizeStringConcat -XX:+AggressiveOpts -XX:ReservedCodeCacheSize=2048m -XX:+UseCodeCacheFlushing -XX:SoftRefLRUPolicyMSPerMB=10000 -XX
arallelGCThreads=10
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 96
FML: MCP 9.42 Powered by Forge 14.23.5.2846 Optifine OptiFine_1.12.2_HD_U_F5 256 mods loaded, 256 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
RebornCore: Plugin Engine: 0
RebornCore Version: 3.16.0.469
Runtime Debofucsation 1
RenderEngine: 1
Ender IO: Found the following problem(s) with your installation (That does NOT mean that Ender IO caused the crash or was involved in it in any way. We add this information to help finding common problems, not as an invitation to post any crash you encounter to Ender IO's issue tracker. Always check the stack trace above to see which mod is most likely failing.):
* Optifine is installed. This is NOT supported.
This may (look up the meaning of 'may' in the dictionary if you're not sure what it means) have caused the error. Try reproducing the crash WITHOUT this/these mod(s) before reporting it.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!You are looking at the diagnostics information, not at the crash. !!!
!!!Scroll up until you see the line with '---- Minecraft Crash Report ----'!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
AE2 Integration: IC2:ON, RC:ON, MFR:OFF, Waila:OFF, InvTweaks:ON, JEI:ON, Mekanism:OFF, OpenComputers:OFF, THE_ONE_PROBE:ON, TESLA:OFF, CRAFTTWEAKER:ON
Suspected Mods: Unknown
