What troubleshooting steps have you tried? Have you tried a 4 second reset or 40 second system restore?
http://support.wdc.com/KnowledgeBase/answer.aspx?ID=13986
If you have a lot of media/files on the drive it may take the My Cloud some time (perhaps hours) to rescan and catalog all of the content.
If you do a subforum search via the magnifying glass icon upper right you’ll find several threads that discuss how to downgrade the My Cloud to a previous firmware version. The following is one such link that lists the prior firmware versions and where they can be obtained along with how to downgrade.
https://community.wd.com/t/wd-my-cloud-v4-x-and-v2-x-firmware-versions-download-links/148533
Note however that downgrading the firmware may cause problems with remote access or with the WD My Cloud software or apps.
