in tei-divtypeapparatus.xsl Oxygen 17 (but not Ox13) reports an error on line 25 , claiming that the template named "source" does not declare the parameter parm-external-app-style. As far as I can see it does, and as I say Oxygen 13 doesn't have this problem, but in any case this bug needs to be resolved, as a matter of some urgency, I'd say.
Fixed in [r2382]. Tunnel parameters have to be declared as such.
Related
Commit: [r2382]