Why is DAZ suddenly reading some skin shaders as "Custom"?

Hello -

I had an entire legion of characters set up (for rendering in 3Delight) with displacement maps for vascularity, bump maps, etc., using primarily the omnifreaker shader. All of a sudden, when I open scene files with those characters, the shader reads as "Custom" and my displacement maps are gone. Why is this? I'm getting tired of re-doing characters after laborious setup. Why does DAZ seem to do whatever it pleases of late, seemingly without cause?

Thank you.