Missing Layers on X-ref Dwg

[Anonymous]

There seems to be some layers missing in this x-ref drawing. I can still see how it originally looked like in the thumbnail in the Recent Documents column (entitled "x-site"), but when I open it up, there is a lot of stuff missing.

I've verified that all the layers are turned on. The last thing I remember doing before all the stuff disappeared is writing the drawing as a block so that I could import/insert it into another drawing. Why is all this content missing and how do I get them back? I've attached a screenshot of the thumbnail that shows how the drawing originally looked like vs. how it looks like whenever I open it up.

[rkmcswain]

You can't go off of thumbnail images. That is just a snapshot of what it looked like at the time of the last save. Reference drawings and other reference items such as shapes, fonts, etc. can be modified, moved, deleted, etc. since the time the image was captured.