Just to clarify a little about WHY it’s risky to locate SEW projects on Dropbox (since a few people have asked me why they shouldn’t do this with SEW, InDesign, etc.), here’s a quick overview.
When you’re editing a document, most software will have several files open at once, covering different part of the main document. During the editing process, the document is no longer a single file. With SEW and certain other editors (e.g., Scrivener, MAC editors), a document is never a single file – it’s a folder full of fragments in their own files. These fragment files are managed by the editor software so the whole process feels like editing a single document file, but it’s not.
The upshot of all this is that when you stop editing, several different files have to be safely written to the cloud before the document is fully closed and saved. Unfortunately, Dropbox (and the cloud itself) is subject to the performance limitations of the internet, so that last file update might not happen until several minutes after you have exited SEW (or InDesign or Scrivener, etc.). In other words, there’s no failsafe way to be absolutely certain when your document is fully saved in the cloud.
Re-opening a cloud document, on the same pc or on a different one, runs the risk of starting to make new changes on files that are not (yet) truly current. The variety of things that can go mysteriously wrong because of this is not only surprising, but also hard to detect and manage.
That’s why using this kind of editing software on cloud-based documents is generally considered to be Very Risky Business.