For we Syncing "Idiots"

For those, like me, who knew the answer was staring them in the face, I finally figured out how to stare back. I had a DropBox account, but I had never downloaded the DropBox app. (I just went on via the web). You need to download the app on both your laptop (desktop) and iPad (tablet). Hope that helps someone else. My files are now syncing and I’m going out for a drink.

Cheers.

Not to be argumentative, but it appears that you only need the DropBox client on the PC (OS X or Windows) side. Having the DropBox app on the iOS side is not necessary (Scrivener for iOS contains its own complete DropBox code) and tends to confuse the issue (being sandboxed/segregated like other iOS apps, it cannot directly provide DropBox services to other apps).
https://forum.literatureandlatte.com/t/scrivener-crashing-on-ipad/34128/1

Yes, yes. You’re right. It was the MacBook side where I was making the mistake.