I'm using Sublime Text 3.
I keep my sublime projects in a Dropbox folder, so I can work on them on multiple computers. The projects themselves are about as simple as you could imagine:
The problem I'm having is, I believe, related to the fact that the Dropbox folders have different locations on my computers. On one computer, it's D:\Dropbox. On another, it's C:\Users[my name]\Dropbox\cosmic.
I'm unable to open projects, often on either computer, getting an error along the lines of "Unable to read project /D/Dropbox/cosmic/Cosmic.sublime-project". I'm getting this error on the computer where Dropbox is on the C drive, so it's trying to look in the directory from the other computer. After getting this error, ST will sometimes open the last files I had open, sometimes not, but it won't load the folder into the sidebar, and I'll have weird behavior in ST until I click "Close Project" and restart it.
I never had any issues like this in Sublime Text 2, and used the exact same setup.