I've been playing with Parley for some time and I can't seem to get Example Training to work. I add sentences in the example columns and configure training to example but when I start the practice I always get the error that the vocabulary document does not contain entries that can be used for the chosen type of practice.

Any ideas what I could be doing wrong ?

You could try to switch the from/to languages of the practice - example sentences only belong to one language, so if you select to learn that language, they are available. There is one document that contains working example sentences in the download section - "Basic vocabulary German-English".
Also try to select all lessons (check boxes).

I hope that helps,
Frederik