Versions

Minecraft Version: 1.12.2
Extended Days Version: 0.2.4
Silent Lib Version: 2.3.1

Expected behavior

Actual behaviour

Only the sun and moon textures displayed correctly

Steps to reproduce the problem

Just put in a resourcepack with custom skies.
Custom skies used in screenshots

Not sure if this is fixable, but I'll look into it. You may just have to disable Extended Days' custom renderer (under the "client" category in the config, I think).

So the custom sky textures are working again.
But the sky moves like default minecraft without mods and the sun/moon stops at their maximum height and won't move

Might be fixed in version 0.2.5.