right beside “Cloud Service”, click on “Configure…” and then click Content Database Rebuild button.
Maybe the database for the web access via My Cloud is corrupted, this will re-index the stored data. But be patient, it may last a while until the process has finished.
Other possibility would be, the recycle bin(s) need to be cleaned: Settings → General → Services (at the end of the page) → Clear recycle bin
I don’t know how many time takes the database to rebuild itself, but after three hours the situation remain the same.
I noticed an alert regarding ORION_LOG but, honestly, i do not understand the message:
FYI:
I tried to re-apply the last firmware 1.05.30 in order to refresh eventually misconfigured settings.
I tried to re-format the disk drives and click the Settings->Utilities->System Restore->System Restore
I tried also to press the reset button for 4 seconds (factory reset?)
Nothing worked: after some days (File History copied 260Gb of files) the problem returns.