EDI Translators are expensive, but worth it if you have more than just a very few trading partners. I would suggest that approach before writing your own.
Secondly, if I was going to expend the effort to write my own translator, I would be run, not walk, away from any module that generated warnings saying something in it is 'experimental'. Is it something that is going to change functionality or just go away in a future release? Is all my hard work going to be wasted?
Is your test data well formed? I work with X12, not EDIFACT, so I can't tell just by looking. That might be the source of the error. If not, I think you need to open up the module and go to the line indicated and see what it was trying to do.