Disappearing Levels

[JamesVan]

Has anyone seen levels disappear in their project? A couple of my levels have vanished from all elevations and sections. The views are still in the browser, but no symbols. I tried deleting the views in the browser and making new levels, but I can't rename them as the original ones still exist somewhere.

Thoughts?

[JamesVan]

Oops again. This one was a bit tricky. I did not know you could put levels on worksets other than "Shared Levels and Grids". The disappearing levels were on a Structural workset which I did not have open at the time.

Be aware of this important gotcha.