If the client is using a Domain Controller, and are running it on a virtual machine with insufficient horsepower, then the failure of the domain controller to properly authenticate a file access in the requisite time will result in denial of access (as though the network cord has been unceremoniously yanked from the machine). This makes Adagio VERY unhappy, and it doesn't have many ways to complain about a file suddenly "disappearing".

A virus checker insisting on scanning a large database can make it appear to "disappear" to the application. Again, this makes Adagio very unhappy.