Has anyone gotten dita working with EPIC 5?

I'm getting compilation errors when trying to create a new doc type in
EPIC.

Here's one of the errors:

Dtgen.exe Parser Error:
While parsing file C:\dita\dita13\dtd\topic.dtd:
The varname model token has been used ambiguously within the model of
filepath.
The parser must be able to choose a model token without look-ahead
(err:506 line:78 pos:3253)
Compile failed - rc=32

TIA

Ilana