What happened?

Activating a sticky piston with redstone sometimes causes the items in the hotbar and inventory to turn black. Also all text (chat, buttons, ...) turns black. Reloading shader packs does not work, issue even exists on title screen after leaving world. Can be temporarily fixed by mining any block.

Screenshots

Log output

none

Minecraft Version

1.21.3

Iris Version

1.8.0+mc1.21.3

Operating System

macOS 15.1

What is your GPU?

Apple M1 Ultra

Additional context

Tested with multiple shader packs (Complementary, BSL, ...) Only happens on 1.21.3 Fabric and NeoForge.
Other mods: Sodium, Fabric API

Thanks for highlighting this! I’ve had the same shader rendering issue with Iris and thought it was just my setup. Glad to see it’s not just me—looking forward to a fix!

same issue here (M3 Max, Fabric, Iris, Sodium) - it always happens when holding no item in my hand and activating piston - items restore when changing to filled slot in inventory

Same issue here 1.21.3 on a M2 Pro

Also happens on 1.21.4

Yep, same here, using an M1 MBP. As soon as any shaders are loaded (Complementary or Photon) and a piston activates, the GUI & other faults described above happen. Always get the following line in the log when it happens:

UNSUPPORTED (log once): POSSIBLE ISSUE: unit 0 GLD_TEXTURE_INDEX_2D is unloadable and bound to sampler type (Float) - using zero texture because texture unloadable