Hi,
Glad to read you fixed your issues but:
- you're using a very very very old version of Cross. You should update to the latest one (go in the download center of this forum).
- there's no issue in the manual with the the 3rd output. In "External Mixer" mode, this output is used for "collection previewing".
You're not obliged to use nor connect it, but you can.
But maybe you fought against some bug in this ancestral version...
You probably never told your weren't using a recent version, and unfortunately nobody's asked you.
Next time you have an issue, don't forget to post a pic like this

Cheers,