Missing textures for mobs, only bounding box shown. Log is flooded with "java.lang.IllegalStateException: Vertex buffer is not uploaded: UNLOADED"

[mlt]

I downloaded an older PaperMC with 1.20.4 network protocol version. Somehow I can see pigs only. Most mobs are not rendered. I built from master with MS jdk 21. Am I missing something?
Probably related, but I also cannot see (even bounding box) a player on Bedrock edition (Geyser & Floodgate plugins). The other user can see me on their iPad.

console log

[2026-06-18 21:09:27.524] [Worker#0] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_0.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_0.png
[2026-06-18 21:09:27.524] [Worker#6] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_1.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_1.png
[2026-06-18 21:09:27.524] [Worker#4] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_3.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_3.png
[2026-06-18 21:09:27.524] [Worker#2] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_2.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_2.png
[2026-06-18 21:09:27.524] [Worker#7] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_4.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_4.png
[2026-06-18 21:09:27.524] [Worker#5] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_5.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_5.png
[2026-06-18 21:09:27.529] [Audio#1] [AUDIO] [INFO] OpenAL loaded!
[2026-06-18 21:09:27.536] [Worker#5] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_6.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_6.png
[2026-06-18 21:09:27.537] [Worker#7] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_7.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_7.png
[2026-06-18 21:09:27.541] [Worker#6] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_8.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_8.png
[2026-06-18 21:09:27.542] [Worker#1] [RENDERING] [WARN] Can not load texture minecraft:textures/blocks/destroy_stage_9.png: java.io.FileNotFoundException: Can not find asset minecraft:textures/blocks/destroy_stage_9.png
[2026-06-18 21:09:29.093] [RenderingPool#2] [LOADING] [WARN] Can not find item model minecraft:builtin/generated
[2026-06-18 21:09:29.133] [RenderingPool#2] [LOADING] [WARN] Can not find item model minecraft:builtin/entity
[2026-06-18 21:09:30.269] [Rendering#1] [LOADING] [WARN] Can not find skeletal model minecraft:models/entities/pig/piglet.smodel
[2026-06-18 21:09:30.277] [Rendering#1] [LOADING] [WARN] Can not find skeletal model minecraft:models/entities/cow/calf.smodel
[2026-06-18 21:09:32.263] [Rendering#1] [RENDERING] [INFO] Rendering is fully prepared in 5.0 s
[2026-06-18 21:09:32.263] [Rendering#1] [NETWORK] [INFO] Connecting to server: localhost
[2026-06-18 21:09:32.464] [Nio#2] [LOADING] [WARN] Can not find registry: minecraft:trim_pattern
[2026-06-18 21:09:32.464] [Nio#2] [LOADING] [WARN] Can not find registry: minecraft:trim_material
[2026-06-18 21:09:32.679] [Rendering#1] [RENDERING] [INFO] Showing window after 397 ms
[2026-06-18 21:09:32.679] [Rendering#1] [RENDERING] [INFO] Starting loop
[2026-06-18 21:09:32.754] [Nio#2] [CHAT_IN] [INFO] user joined the game
[2026-06-18 21:09:42.779] [Rendering#1] [OTHER] [WARN] java.lang.IllegalStateException: Vertex buffer is not uploaded: UNLOADED
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.system.opengl.buffer.vertex.OpenGlVertexBuffer.unload(OpenGlVertexBuffer.kt:104)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.util.mesh.Mesh.unload(Mesh.kt:33)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.entities.feature.mesh.MeshedFeature.enqueueUnload$lambda$0(MeshedFeature.kt:48)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.kutil.concurrent.queue.Queue.work(Queue.kt:46)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.kutil.concurrent.queue.Queue.work$default(Queue.kt:36)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.entities.EntitiesRenderer.postPrepareDraw(EntitiesRenderer.kt:83)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.renderer.renderer.RendererManager.prepare(RendererManager.kt:116)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.renderer.renderer.RendererManager.draw(RendererManager.kt:122)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.RenderLoop.loop(RenderLoop.kt:75)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.RenderLoop.startLoop(RenderLoop.kt:131)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.Rendering.startRenderWindow(Rendering.kt:79)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.Rendering.startRenderWindowThread$lambda$0(Rendering.kt:68)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at java.base/java.lang.Thread.run(Thread.java:1583)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN] java.lang.IllegalStateException: Vertex buffer is not uploaded: UNLOADED
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.system.opengl.buffer.vertex.OpenGlVertexBuffer.unload(OpenGlVertexBuffer.kt:104)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.util.mesh.Mesh.unload(Mesh.kt:33)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.entities.feature.mesh.MeshedFeature.enqueueUnload$lambda$0(MeshedFeature.kt:48)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.kutil.concurrent.queue.Queue.work(Queue.kt:46)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.kutil.concurrent.queue.Queue.work$default(Queue.kt:36)
[2026-06-18 21:09:42.780] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.entities.EntitiesRenderer.postPrepareDraw(EntitiesRenderer.kt:83)
[2026-06-18 21:09:42.781] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.renderer.renderer.RendererManager.prepare(RendererManager.kt:116)
[2026-06-18 21:09:42.781] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.renderer.renderer.RendererManager.draw(RendererManager.kt:122)
[2026-06-18 21:09:42.781] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.RenderLoop.loop(RenderLoop.kt:75)
[2026-06-18 21:09:42.781] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.RenderLoop.startLoop(RenderLoop.kt:131)
[2026-06-18 21:09:42.781] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.Rendering.startRenderWindow(Rendering.kt:79)
[2026-06-18 21:09:42.781] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.Rendering.startRenderWindowThread$lambda$0(Rendering.kt:68)
[2026-06-18 21:09:42.781] [Rendering#1] [OTHER] [WARN]   at java.base/java.lang.Thread.run(Thread.java:1583)
[2026-06-18 21:09:42.832] [Rendering#1] [OTHER] [WARN] java.lang.IllegalStateException: Vertex buffer is not uploaded: UNLOADED
[2026-06-18 21:09:42.832] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.system.opengl.buffer.vertex.OpenGlVertexBuffer.unload(OpenGlVertexBuffer.kt:104)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.util.mesh.Mesh.unload(Mesh.kt:33)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.entities.feature.mesh.MeshedFeature.enqueueUnload$lambda$0(MeshedFeature.kt:48)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.kutil.concurrent.queue.Queue.work(Queue.kt:46)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.kutil.concurrent.queue.Queue.work$default(Queue.kt:36)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.entities.EntitiesRenderer.postPrepareDraw(EntitiesRenderer.kt:83)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.renderer.renderer.RendererManager.prepare(RendererManager.kt:116)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.renderer.renderer.RendererManager.draw(RendererManager.kt:122)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.RenderLoop.loop(RenderLoop.kt:75)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.RenderLoop.startLoop(RenderLoop.kt:131)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.Rendering.startRenderWindow(Rendering.kt:79)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at de.bixilon.minosoft.gui.rendering.Rendering.startRenderWindowThread$lambda$0(Rendering.kt:68)
[2026-06-18 21:09:42.833] [Rendering#1] [OTHER] [WARN]   at java.base/java.lang.Thread.run(Thread.java:1583)

[Bixilon]

Hi,

correct. Almost all other entities are not implemented (I got bored on the way). See https://github.com/Bixilon/Minosoft/tree/master/src/main/resources/assets/minecraft/models/entities. Feel free to implement more models :)

The exceptions you are seeing should not be there, indeed. That is a recent change in kutil 1.31, errors in the queue (are printed), however they should normally crash minosoft. I will look into it (probably next week).