I have had problems on the Mac and to some extent Windows as well. Generally the fix has been to totally close Dropbox, clear out the Dropbox cache, which is a set of hidden files somewhere (look in their support pages or Google for it) and then re-install the Dropbox application. It more than likely will do a full re-index and this is an absolute pain and CPU hog when it happens. If you have a lot of files, it can day half a day to a full day.<p>I&#x27;m not sure exactly what happens, but my guess is that somehow an index in it&#x27;s internal database gets corrupted and then it sits in a loop there for some reason whenever it hits that file&#x2F;folder.<p>We have used Dropbox extensively in our office across Windows &amp; OSX for at least 2 years and have had this periodically (and randomly) happen on some machines. Although I can&#x27;t recall it happening in the last 6 months or so.<p>There was a period where it happened almost fortnightly to someone in the office and we almost swore off Dropbox to something else.<p>The above has always fixed the issue for us. YMMV.