Cyberduck is a libre FTP, SFTP, WebDAV, Amazon S3, Backblaze B2, Microsoft Azure & OneDrive and OpenStack Swift file transfer client for Mac and Windows.
Can you find any related output in the console.log (/Applications/Utilities/Console.app)? Do you have WindowDragon installed? If so, put Cyberduck on the exclusion list. Otherwise, please post the output from console.log (Applications/Utilities/Console.app).
Versions 2.x are working fine, 3.x crashes at start time:
Can you find any related output in the console.log (/Applications/Utilities/Console.app)? Do you have WindowDragon installed? If so, put Cyberduck on the exclusion list. Otherwise, please post the output from console.log (Applications/Utilities/Console.app).