According to Mylio’s activity view the software is currently “Syncing attached storage device(s)” and “Protecting files to online Vault”. I have not setup any cloud-based vault. What is happening when the software is “protecting files to online Vault”? I’ve found very little reference to the phrase “online vault” anyway… Thanks! 
-Brett
The terminology has recently changed regarding vaults - they now seem to be called ‘devices containing originals’ in Mylio, and it’s a bit inconsistent at the moment. An ‘online vault’ is simply a device that contains originals that is presently connected to Mylio, such as an external hard drive or NAS. It doesn’t necessarily mean cloud-based. This is an older use of the term ‘online’ that pre-dates the Internet!
Mylio was telling you that it was bringing a device containing copies of your original images up to date.