I have recently encountered a problem where features such as holes seem to be disappearing from part files.  I opened an assembly this morning that I had finished yesterday and received several mate error messages.  Upon inspection, it appeared that nearly half of the holes and extruded cut features on one of the assembly parts were gone.  The features are not listed in the feature tree for the part as though they never existed.

This has happened several times over the last few weeks.  This also happened to a part in an older assembly, a part no one has worked on or changed in months.

The only way I've been able to 'catch' this happening is by getting mate errors when I open assemblies, and am concerned this may be happening to other parts without us knowing.

We recently switched from using Dropbox to an internal server, which has caused some issues saving files, not sure if that is connected.  The parts I've had problems with seem to save fine but then are missing features when opened in the future.

Anyone have any ideas?