Version Info

• Minecraft 1.12.2
• Tesseract-1.0.24-mc1.12
• OptiFine_1.12.2_HD_U_G5
• ComplementaryShaders_v4.2.2

Description of the Bug
When shaders are turned on, the "ender portal effect" inside Tesseract become black and slightly flickers.
No light is emitted unlike the regular texture of the ender portal.

Screenshots
Regular ender portal using shaders:

Tesseract using shaders:

Nothing I can do about this sadly, I have no control over the shaders.