I am working with two parts that were built using scan data as reference geometry.  The scan data was imported using scan to 3D.  I have an assembly that contains both parts and a few others.

Here's the thing:  everything seems fine, and then after a period of time the scan data/mesh just disappears - from both the assembly and the underlying part files.  Happens to both of them at the same time.  The "mesh" still shows in the feature tree, but you can't show/hide it (that option is gone from the menu).  Solidworks no longer even recognizes it as a mesh/point cloud file - if you go to the "Scan to 3D" menu the edit options are grayed out (see attached screenshot).

If I load a previously saved version of the files, everything is fine, so it is definitely related to the file itself.

Any thoughts?  Any help much appreciated, this is a real bummer - the only way to deal with it is to revert to a previous version and redo any lost work.

Thanks in advance!