I'm having a major issue with a relatively large assembly.

At least half of the parts, and in some cases entire assemblies, have disappeared.  In many cases, all I will see are a few fasteners (no, I am not using toolbox).

Note that when I say "disappeared", I mean they are not visible. The files, feature tree, and linking to the assembly is still 100% intact (thank god).

The only way to "fix" this is to open up each assembly, and open up each individual invisible part and do a CTRL-Q rebuild.

This is VERY tedious, and I'm worried that I'm missing a lot of parts.

What's the easiest way to fix it?

What has disappeared seems completely random.

Thanks for any help.