Did you use DriveHQ FileManager client software or the website directly? It is recommended using DriveHQ FileManager for uploading files.
You can also use the website or FTP to upload files. If it doesn't work, please email us more detailed error message, or a screenshot.
If you would like to use FTP, Windows Explorer can be used as a simple FTP client, just enter the path:
ftp://USERNAME:PASSWORD@ftp.drivehq.com/