Hi topsurfer,
Unfortunately, we stopped supporting Boxcryptor Classic on new platforms, such as Windows 10, Mac OS X 10.11 "El Capitan", iOS9 etc.
Furthermore, we discontinued to support Boxcryptor Classic since 2017. I am sorry for the inconvenience.
Of course we tried hard to keep Boxcryptor Classic alive as long as possible.
But since Dropbox is discontinuing their old Dropbox API v1, Boxcryptor Classic will also no longer be able to connect to Dropbox on mobile devices.
Please have a look here: https://blogs.dropbox.com/developers/2017/09/api-v1-shutdown-details/
I would strongly suggest you to upgrade to Boxcryptor, because this version is supported on the new operating systems.
Please note: Boxcryptor Classic and Boxcryptor are _not_ compatible to each other.
Meaning, you may not access Boxcryptor Classic encrypted files using Boxcryptor and vice versa.
Mac:
To decrypt your existing data on an older macOS version, you should update Boxcryptor classic.
You will then have the possibility to decrypt and migrate your encrypted data.
You may find the download here:
https://www.boxcryptor.com/download/Boxcryptor_Installer.dmg (read only)
On Mac OS X 10.12 "Sierra" there are more Apple-restrictions.
To mount Boxcryptor Classic there, please use this version:
https://www.dropbox.com/s/eielq4ehhv2tdwt/Boxcryptor_Classic_v1.5.417.253_Installer.dmg?dl=0
Please note, Boxcryptor will not run on Mac OS X 10.13 "High Sierra" and above.
Windows:
To decrypt your files on Windows 10 you may use Boxcryptor Classic Portable.
You may find the download here:
http://www.boxcryptor.com/download/Boxcryptor_Classic_Portable.zip
The next step would be to create a Boxcryptor Account and download the latest release for your system.
You may find the download here: https://www.boxcryptor.com/download/
To migrate you files please carefully follow these instructions:
https://www.dropbox.com/sh/x3walxmza6oqydw/AABBWFYf80FmDKvTBqXqaEWga?dl=0
I hope this helps your transition to Boxcryptor.
Kind regards,
Richard