Missing chapters moving Scrivener from PC to Mac via dropbox

I started working with Scrivener on a PC and have kept the project synced with dropbox. This week I got a Mac and downloaded the Mac version, then picked up my manuscript through Dropbox.
Fairly succesful, though a couple of chapters are simply missing when I open scrivener on the Mac. They are still there on the pc, and any new changes done on either Mac or Pc are registered.

Question 1: What went wrong? (I know for sure that the pc was turned off and synced when I installed everything on the Mac)

Question 2: More importantly, which is the easiest way to move those missing chapters onto the Mac and into the manuscript? I’ll mainly be working on the Mac in the future, so would like to have my entire project there.

On the windows side, do a search in the project folder for “conflicted” and see if that turns up anything. If that doesn’t pan out, then try creating new documents on the mac; if for some reason a file goes missing from the binder, then sometimes creating a new file reveals the text, since all the files are internally just named 1.rtf, 2.rtf and similar, so “creating” a new file in Scrivener will just link up the new item in the interfacd with the existing 57.rtf file, for instance.