I see a couple potential problems with Poser OBJ files.

Some Poser OBJ files contain group tags with the same names, so
some programs who think every group tag is unique, will try to
create all those groups, which could be hundreds of groups,
when actually there are only a dozen or so.

Also, a lot of Poser OBJ files terminate each line with only a
line feed, not the typical line feed+newline pair. This looks
like a black square in MS Notepad, because there is no newline
character. This is bad for programs not expecting this, because
the program might think the entire file is on a single line,
so it won't find anything.

But you can easily fix the second problem, by copying and pasting
the entire OBJ file into MS WordPad, and save the file as a text
document. This should add the line feed+newline tags back to
the text file.

Probably have to email the author about the first problem.
Seems like an easy fix though.