The game can crash when loading OIT shaders even with the "Improved Transparency" option disabled

The following was written with the assistance of Claude Code:

STEPS TO REPRODUCE:

1. On a GPU that cannot meet OIT's shader requirements (any pre-GCN AMD GPU or similarly old hardware), launch 26.3-snapshot-2.

1. Confirm options.txt has improvedTransparency:false.

1. Launch normally, vanilla, no mods.

EXPECTED RESULT:

Per the snapshot's own changelog, with improvedTransparency off the behavior should not meaningfully change from pre-OIT versions. The game should launch using legacy transparency, the same as it did on 26.2.

Separately, Mojang's own stated design intent for the broader Vulkan migration is: Vulkan is not supported by older hardware or drivers, OpenGL will be used as a fallback in those cases. The game should therefore either launch normally on OpenGL with legacy transparency, or at minimum fail gracefully with an informative message, rather than crash to desktop.

ACTUAL RESULT:

Crashes on Reload reason: initial while eagerly compiling all 34 oit_accumulate_* and oit_composite pipeline shaders, regardless of the improvedTransparency setting. Confirmed identical with and without a system Vulkan loader present (Graphics Backend: OpenGL both times) - this is a pure OpenGL-path failure, not Vulkan-specific.

CRASH LOG (java.lang.RuntimeException):

java.util.concurrent.CompletionException: java.lang.RuntimeException: Failed to load required shader programs:

• minecraft:pipeline/oit_accumulate_breeze_wind

• minecraft:pipeline/oit_accumulate_world_border

• minecraft:pipeline/oit_accumulate_entity_shadow

• minecraft:pipeline/oit_accumulate_terrain

• minecraft:pipeline/oit_accumulate_text_see_through

• minecraft:pipeline/oit_accumulate_text_grayscale_see_through

• minecraft:pipeline/oit_accumulate_lines_translucent

• minecraft:pipeline/oit_accumulate_item_glint_special

• minecraft:pipeline/oit_accumulate_text_grayscale_polygon_offset

• minecraft:pipeline/oit_accumulate_text_polygon_offset

• minecraft:pipeline/oit_accumulate_text_background_see_through

• minecraft:pipeline/oit_accumulate_dragon_rays

• minecraft:pipeline/oit_accumulate_eyes

• minecraft:pipeline/oit_accumulate_debug_triangle_fan

• minecraft:pipeline/oit_accumulate_item_glint

• minecraft:pipeline/oit_accumulate_item

• minecraft:pipeline/oit_accumulate_flat_clouds

• minecraft:pipeline/oit_accumulate_weather

• minecraft:pipeline/oit_accumulate_energy_swirl

• minecraft:pipeline/oit_accumulate_lightning

• minecraft:pipeline/oit_accumulate_text_background

• minecraft:pipeline/oit_accumulate_entity_cull

• minecraft:pipeline/oit_accumulate_particle

• minecraft:pipeline/oit_accumulate_text_grayscale

• minecraft:pipeline/oit_accumulate_clouds

• minecraft:pipeline/oit_accumulate_debug_filled_box

• minecraft:pipeline/oit_accumulate_text

• minecraft:pipeline/oit_accumulate_entity_emissive

• minecraft:pipeline/oit_composite

• minecraft:pipeline/oit_accumulate_beacon_beam

• minecraft:pipeline/oit_accumulate_translucent_block

• minecraft:pipeline/oit_accumulate_debug_points

• minecraft:pipeline/oit_accumulate_crumbling

• minecraft:pipeline/oit_accumulate_debug_quads

• minecraft:pipeline/oit_accumulate_entity

• minecraft:pipeline/oit_accumulate_secondary_block_outline

at net.minecraft.client.renderer.ShaderManager.apply(ShaderManager.java:170)

at net.minecraft.client.renderer.ShaderManager.apply(ShaderManager.java:43)

at net.minecraft.server.packs.resources.SimplePreparableReloadListener.lambda$reload$1(SimplePreparableReloadListener.java:15)

RELEVANT CRASH REPORT FIELDS:

Reload number: 1

Reload reason: initial

Finished: No

Packs: vanilla, vanilla

Launched Version: 26.3-snapshot-2

Backend library: LWJGL version 3.4.1+2

Graphics Device: ATI Mobility Radeon HD 4300 Series

Graphics Backend: OpenGL

Graphics Vendor: ATI Technologies Inc.

Graphics Drivers: 3.3.11672 Core Profile Forward-Compatible Context

Graphics Device Type: OTHER

Graphics Device Features: DeviceFeatures[shaderDrawParameters=false, multiDrawDirectInterleaved=false, multiDrawDirectSeparate=true, multiDrawIndirect=false, drawIndirect=false, nonZeroFirstInstance=true, persistentMapping=false]

ADDITIONAL NOTES:

On the first reproduction, before a Vulkan loader was present on the system at all, the crash report additionally logged: Backend failure message: Vulkan loader library is missing, Backend failure reason: vulkan_loader_missing. This is a secondary diagnostic note about the Vulkan attempt, not the cause of the crash itself. After installing the official Vulkan Runtime (loader only, no GPU-side ICD), that note disappears but the crash and active backend, OpenGL, are identical, confirming the OIT shader compilation failure is independent of Vulkan availability.

This is on end-of-life hardware (TeraScale 1, AMD's last driver dated 2015) but the underlying bug, improvedTransparency not preventing OIT shader compilation at initial load, likely affects a much wider range of hardware that is merely too old for OIT but otherwise capable of running Minecraft's legacy transparency path, the same way it did on 26.2 and earlier.

Suggested fix direction: gate OIT pipeline shader compilation itself behind the improvedTransparency setting or a capability check at initial resource load, instead of compiling unconditionally and only branching on the setting at render time.