Cannot load shaders

[zrll12]

What happened?

I'm using DH, iris, but this shader will report error, and cannot be loaded

Minecraft Version

1.20.1

Which shader mod are you using?

Iris

Shader mod version

1.7.1

Shader settings

I'm using the default setting, so no setting files have been generated.

Relevant log output

No more available texture units while activating sampler shadowtex1

[zrll12]

I'm using MacBook Pro with m2max, metal4.1.
But I do not think this is related to my hardware as it some times can be load under Oculus.
Using older versions without DH support would work.