My model seems fine but when I rotated it, all the lines disappeared leaving only the text from measurements. I closed out and reloaded it but the lines were still gone. I also opened an older version where all of the lines were there and continued designing but when I rotated it, everything disappeared again.
The model had text entities placed somewhere in outer space. Removing them and zooming to extents brought things into view. This usually happens if you place a leader text and then delete the object the leader is pointing at. Master Bedroom Addition - June (1).skp (4.4 MB)
It’s very simple in SketchUp Pro because you can select what you want to keep and then invert the selection and press Delete.
In the free hobby version try turning on Hidden Objects and Hidden Geometry in Display. Then use Zoom Extents. You should be able to see the text entites away from the rest of the model.
Delete them. Then repeat and select the text for Vaulted Ceiling and other stuff that is located at a distance. When Zoom Extents fills the window with your model you should be all set.
With SU Pro you can also select all Leader Text and/or Screen Text by opening the Model Info Window → Text → “Select All Screen Text” and/or “Select all Screen Text”.
Then you close the window and press the Delete key.