Reasons for missing objects - invisible objects in Revit 2008

Here are some reasons an object could be missing / not visible in revit. It is a good idea to go step by step to check:

1. Switch on the light bulb (available at the bottom of the drawing area) to see if the object is hidden. (if so, you can right click on the marooned object and select “unhide”)
2. Check in the VG dialog box if the category is switched off.
   Lines and fill patterns are in the Model category > Detail items. (Dont ask me “why?”)
   If it is an annotation object and if the view is NOT a dependent view, the object won't be visible in other views. (to check if an imported CAD object is an annotation or a model object, click here
3. Check the view range. (View properties dialog box > View range) Detail views have lot of these issues. Revit shows objects only if they are cut or if they are within the view depth
4. check if there are any Plan Regions that have different view ranges / cut plane.
5. Change the view to “wireframe” (available at the bottom of the drawing area) and see if the object is visible. (some other object, like a floor, might be hiding your missing obj)
6. The object could be lying outside the crop bounday. Switch off the 'crop view' option (available at the bottom of the drawing area) and “zoom extents” to check. (CAD files are notorious for this)
7. If you have worksets enabled in your project, check if all workset are on (VG dialog box > worksets) and File menu > worksets (and check in VG > Worksets tab)
8. If the object is hidden, its tags wont be visible (for eg. If the rooms are hidden using the VG setting, the room tags will become invisible too)
9. If it is a family (you might have to open in the Family Editor) check if:
   it just has 2d components; (wont be visible in other views)
   If it has 3D components, check to see whether the 3D object is set to be visible (properties dialog box)
10. If the family uses imported objects from CAD, check (VG dialog box > imported objects tab) imported objects in Family option is ON
11. If it is an Elevation view, check the cut line of the elevation.
    If the cut line is beyond the object, the object wont be visible.
    If the cutline is through the object (wall) then the surface pattern wont be visible!
12. If you use Phases > check if the view is assigned the correct phase and if the object has the correct phase status.
13. If you use Design Options > check if the object is hiding in one of the other design options. (also check "Visible in Option" parameter in the view properties for view tags)
    
14. If you use filters, check if it is active (VG diolog box > Filter tab)
15. Check if the correct "Discipline" is assigned in the View Properties. (Non load bearing walls are not visible if "STructural" discipline is assigned to the view)
    
16. If the object is part of a linked Revit file, thats a whole another blog topic. (the best practice we have found to be useful is to create dedicated views in the linked project and use this view in the host project. )
17. Some more diabolical reasons:
    Someone made all lines that represent the object invisible using the pen tool?
    Or made the line color white in VG or object styles dialog box?
    Or used the “Edit cut profile” tool to make it so small, you cant see it anymore.
18. May be, after all, the object got deleted?!
    Confucius said: “It is difficult to catch a cat that is moving fast. It is more difficult to catch a black cat that is moving around fast in a pitch dark room. However, it is impossible to catch it, if there is no cat at all!”