Hi tomas,
Thank you for reporting this issue.
We have identified this issue is a content defect. The material settings of some eye contents are improperly for digital human shader.
There are two workaround for solving this issue:
Workaround 1: Apply another eye content that can normally work with digital human shader.
Workaround 2: Fix this issue with the following steps,
1.Copy Diffuse/Base Color texture of Std_Eye_R/Std_Eye_L to Std_Cornea_R/Std_Cornea_L
(There should be no Diffuse/Base Color texture before you copy it)
2.Change Diffuse Color of Std_Cornea_R/Std_Cornea_L to White color
(The Diffuse Color should be Black before you change it)
The attached gif is a screen recording of workaround 2, please download to see it. I hope this helps.
Irving
Reallusion