Wonder why your preview is missing when you open a file?

-Find and select this registry key:

REGEDIT under START

HKEY_CURRENT_USER\Software\Autodesk\AutoCAD\R19.0\ACAD-B000:409\Profiles\<<C3D...>>\Dialogs\Select File

-On the right side of the window, double-click "PreviewVisible".

-Change the value to zero and click OK.

-Launch Civil 3D and check the OPEN dialog window. The entire right pane should be gone.

-Exit Civil 3D and then go back into the registry and change the value of PreviewVisible back to 1.

-See if Civil now shows a preview.

Worked for me!! Still annoying, but got it fixed.

Hope this helps.

Contact for more info: sherring@prosoftnet.com