Hi,
In IE11, unless the browser explicetely adds dropbox.com to the trusted sites, the following error occurs when the file picker api was getting executed
The code on this page disabled back and forward caching. For more information, see: http://go.microsoft.com/fwlink/?LinkID=291337
And after that from the picker user cant choose any file as well with the following error

Please note that same dropbox apis to load the file picker and let the user choose the file works in all other browsers.
Can you please let us know what exactly is the reason behind the above mentioned error