Assets disappeared in scene view - checked layers - fine - text shows as brown in Hiearchy tab

Scenes worked fine yesterday - then today when we went to open the project no objects or terrain was showing up in the scene or game view
( if I select an object in the hierarchy view it shows the pivot point of the object) … the particles appear in game view as pink moving objects - but everything else is gone …

in the Hierarchy panel all assets show as brown …

If I drag and drop a new asset over it does appear in scene view … it looks like the original objects are holding their position location but not accessing mesh or material … this is my final project - please help

That sounds like something broke the connections between the files in the scene and the files in the library.

If you have a backup of the project, I would revert to that and see if it fixes the problem. Otherwise, you’re going to have to tell each object where their correct mesh and texture (and script) is.