We have encountered a situation in a file geodatabase where several feature classes that were raster or vector datasets are now being presented as tables through ArcCatalog. We can roughly pinpoint when something happened, but we haven't found an explanation. The cloud environment consists of Netgear ReadyNAS hardware using Egnyte cloud services. By looking at the NAS snapshots I can see the before and after, but Egnyte audit logs don't show anything. I know the file geodatabase OS structure uses many files, is it possible that the removal of one file could account for this?
This could well be the case of file geodatabase corruption. File geodatabase has numerous files associated with it which are responsible for smooth functioning of file geodatabase and its contents using ArcGIS. There could be many factors responsible for file geodatabase corruption, any third party program or function (including windows tools/programs) accessing the file geodatabase contents (files which are stored on the system upon creation of file geodatabase or its contents) in any possible manner may lead to corruption of file geodatabase.
It is always better to store file geodatabase/s in separate folder and then use folder to transfer file geodatabase from one machine to other or even at a different location on the same machine. Any operation should be carried out on a parent folder instead of File geodatabase/s directly (unless using ArcGIS) to minimize or avoid the chances of data corruption.