This Dropbox question was never really off-topic (though its title is a bit confusing):
The best answer to this question is to explain that Dropbox exists natively for Ubuntu, and that the official Ubuntu client should be run rather than attempting to install the Windows version with Wine.
And Roland Taylor has written an excellent answer that explains just that.
There's no reason for this to be closed; I recommend it be reopened. Then that answer can be accepted. (And if somebody wanted to try to answer the question about how to get Dropbox working well using the Windows version in Wine, that would be perfectly on-topic too, since questions and answers about how to get Windows software to work in Wine on Ubuntu are generally considered on-topic).