On 25-October-2016, Intuiface prevented the use of Dropbox by new Intuiface accounts as a cloud storage option for publishing, sharing and deploying Intuiface experiences. This is due to a change in access rights implemented by Dropbox.
For existing users of Dropbox, Dropbox support ended on 28-Sep-2017, meaning all published experiences stored on Dropbox are no longer accessible within Intuiface. (Dropbox originally targeted 28-Jun-2017 for discontinuation of support for vendors like Intuiface but they extended it to 28-Sep-2017.)
You must now migrate your existing projects to Intuiface Cloud Storage by following the steps in the article How to migrate from Dropbox to Intuiface Cloud Storage. (The migration steps would be similar if using your own Amazon S3 bucket or ftp site.)
Why consider using Intuiface Cloud Storage? It is free and - because, under the covers, it runs in the Amazon S3 cloud - it is highly scalable. For more about Intuiface Cloud Storage, see this article.
If you have any questions, please contact Support at http://support.intuiface.com.