Are you getting any errors at all? Mind sharing a screenshot? Also, have you restarted your computer at all recently?
In addition, could you please give our offline installer a go and let me know if this persists?
[EDIT: I forgot to mention that this could be caused by an antivirus or security program running on your Mac computer so the next step here is to temporarily disable any antivirus, firewall or security programs on your computer and reinstall the Dropbox application ( preferrably using the offline installer I provided you with above).]
Did this post help you? If so please give it a Like below. Did this post fix your issue/answer your question? If so please press the 'Accept as Solution' button to help others find it. Still stuck?Ask me a question!(Questions asked in the community will likely receive an answer within 4 hours!)