In August Dave wrote that he learned Dropbox is turning off the API Fargo uses and therefore Fargo will stop working in June 2017. 

If you use Fargo and encrypt outlines, you need to be sure to decrypt them before Fargo stops working otherwise you will likely not be able to access the information in the outline. 

In a response to a post I made to the Fargo users group, I got a link to the Stanford Javascript Crypto Library page, which includes information about the crypto library used in Fargo. It may be possible to utilize this to decrypt files. 

I would add to my feature requests to Little Outliner the ability to encrypt outlines like is available in Fargo.