Created a very simple 3D model using only straight lines and guides. Ran Cleanup3 to check for strays, which reported no errors. Returned to drawing and selected Zoom Extents. Drawing instantly shrank to microscopic size and Zoom Extents no longer has any effect, neither does manual zoom.
Had a similar experience with a previous model, where Zoom Extents had the exact opposite effect, zooming into model and showing an area only hundredths of a millimeter across.
You’ve got something located at a great distance from the origin. Your model isn’t being made microscopic; the camera is zooming out to try to show the whole model space. Zoom in on the geometry at the origin, select it all and copy it. Then paste it into a new file.
I can’t find anything far from the origin in your skp file, but despite that the camera has somehow been moved very far from the model contents. Once that happens, zoom goes nuts and can’t seem to get it right any more. As @DaveR wrote, one fix is to copy paste the contents into a new file. Using an unpublished Ruby, I reset the camera to a sensible place and got the attached. It does not seem to have issues with the camera.
Thanks both.
Dave R’s Cut & Paste tactic worked after I VERY tightly selected the model. I didn’t find a ‘distant object’ after the Ctrl-X, but I had deleted the label before I did the Cut.
If it happens again I’ll do some tests to try and reproduce the glitch.