Yes there are workarounds for the issues you are experiencing.
Check these posts in the FAQs.
http://community.wd.com/t5/WD-My-Cloud/before-you-pack-up-your-WD-and-return-it-let-s-talk-about/m-p/683307/highlight/true#M7901
Firstly, you can stop the scanning services by following this guide:
http://community.wd.com/t5/WD-My-Cloud/Hidden-wdmc-directories-created-by-mcserver-and-photodbmerger/m-p/682091/highlight/true#M7765
This should stabilise your device, which will allow you to downgrade the firmware to v3. Make sure to disconnect any USB connected device before you start.
http://community.wd.com/t5/WD-My-Cloud/Tutorial-SSH-Method-Downgrade-v4-firmware-to-v3/m-p/812311#M23232
As soon as the downgrade is complete, turn off auto-update firmware and media scanning. You will then need to redo the steps above to kill the scanning services.
The downgraded firmware will be more stable and also allow you to use USB attached device for backups.
Next, you should check that your data is structured correctly for correct Twonky operation. Read this next:
http://community.wd.com/t5/WD-My-Cloud/FAQ-Twonky-DLNA-Media-Server-Setup-amp-Use/td-p/858810
Once you are done with that, you should be safe to turn on DLNA media server.
