Loading bar finishes but then goes back down

[Ear_thy]

20:51:12.244
game
[20:51:12] [Render thread/INFO] [quark/]: Dispatching Module Step POST_TEXTURE_STITCH
20:51:12.244
game
[20:51:12] [Render thread/INFO] [minecraft/TextureAtlas]: Created: 512x512x4 minecraft:textures/atlas/banner_patterns.png-atlas
20:51:12.249
game
[20:51:12] [Render thread/INFO] [quark/]: Dispatching Module Step POST_TEXTURE_STITCH
20:51:12.249
game
[20:51:12] [Render thread/INFO] [minecraft/TextureAtlas]: Created: 512x512x4 minecraft:textures/atlas/shield_patterns.png-atlas
20:51:12.254
game
[20:51:12] [Render thread/INFO] [quark/]: Dispatching Module Step POST_TEXTURE_STITCH
20:51:12.255
game
[20:51:12] [Render thread/INFO] [minecraft/TextureAtlas]: Created: 1024x1024x4 minecraft:textures/atlas/chest.png-atlas
20:51:12.270
game
[20:51:12] [Render thread/INFO] [quark/]: Dispatching Module Step POST_TEXTURE_STITCH
20:51:12.270
game
[20:51:12] [Render thread/INFO] [minecraft/TextureAtlas]: Created: 512x256x4 minecraft:textures/atlas/beds.png-atlas
20:51:12.272
game
[20:51:12] [Render thread/INFO] [quark/]: Dispatching Module Step POST_TEXTURE_STITCH
20:51:12.272
game
[20:51:12] [Render thread/INFO] [minecraft/TextureAtlas]: Created: 512x256x4 minecraft:textures/atlas/shulker_boxes.png-atlas
20:51:12.274
game
[20:51:12] [Render thread/INFO] [quark/]: Dispatching Module Step POST_TEXTURE_STITCH
20:51:13.993
game
[20:51:13] [Render thread/WARN] [ne.mi.cl.mo.SeparateTransformsModel/]: Model "cave_enhancements:amethyst_flute#inventory" is using the deprecated loader "forge:separate-perspective" instead of "forge:separate_transforms". This loader will be removed in 1.20.
20:51:48.195
game
Exception in thread "Thread-0" java.lang.OutOfMemoryError: Java heap space
20:51:48.195
game
at java.base/java.util.concurrent.ConcurrentHashMap$ValuesView.iterator(ConcurrentHashMap.java:4740)
20:51:48.195
game
at MC-BOOTSTRAP/[email protected]/com.electronwill.nightconfig.core.file.FileWatcher$WatcherThread.run(FileWatcher.java:162)
21:08:16.538
game
[21:08:16] [Render thread/INFO] [minecraft/Minecraft]: Stopping!
21:08:17.427
monitor
Process Monitor
Process ended with exit code 0

 

[Luis_ST]

The game is running out of Memory (RAM).
You need to give the game more Memory.

[Ear_thy]

10 hours ago, Luis_ST said:

The game is running out of Memory (RAM).
You need to give the game more Memory.

how do i do that

[Luis_ST]

Due the log i would guess you are not running a server.
The this depends on your Launcher. I only know the solution for the vanilla Launcher (include CurseForge):
Go into the installations tab, edit the profile you are using. Open the more options and edit the JVM arguments and modify the -Xmx argument.
The default value is 2G which are 2 Gigabyte, you can try to use 4G or 6G (you should choose a value based on the installed memory).

If you start a server against my assumption, you can add/modify the -Xmx argument in the user_jvm_args file.