how long is a cursor valid for?

[Cross-linking for reference: https://stackoverflow.com/questions/39135256/dropbox-api-cursors-how-long-are-they-valid-for-and-using-them-properly-over-ti ]

Cursors don't expire (but they can be "reset").

To stay up to date though, you shouldn't call listFolderGetLatestCursor after you've already begun getting a listing. Instead, you should use the last cursor returned from listFolder or listFolderContinue. 

Please try that out and let me know if you're still having trouble, and if so, please share your latest code. (I notice your code is a bit different between here and your StackOverflow post, so I'm not sure exactly what you're doing.)