Zbrush doesnt perform uv map because "mesh containes closed shells"

[silverland]

how to solve this problem? never had this before. I created proper uv seams in Maya and exported object as obj in zbrush and when i use "Zplugin uv master " uv unwrap with “USE EXISTING UV SEAMS” it shows me this problem. what does it mean and how to fix it?

Attachments

[marcus_civis]

Whatever seams you created can’t be used by UV Master. Typically this is because you have closed volumes in your mesh which you’ve not created seams for.