In the UVmapper export box, you say everything is checked.  Most of those checks are negative, as in "Don't export .....".   So you're getting a result that *doesn't* include most of the things Poser needs.  No materials, so it's not surprising that the whole thing looks white.

The default in Windows is to have everything UNchecked except 
for "Don't export normals".  For a Mac I think you'd also want to check
"Don't export linefeeds."  Could be wrong about that....

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