Is MyCloud Drive corrupted? (400044 error)

You can hook the internal hard drive of the My Cloud up to a computer running Linux (or a Linux plug in for Windows) and view the contents of the hard drive.

There are other programs like WinSCP (https://winscp.net/eng/index.php) that can be used to view the contents of the My Cloud (via SSH) which behave similar to using a file manager. That will alleviate the need to know various Linux command line codes to navigate the directory structure of the My Cloud.