After recent upgrade, missing images

I allowed the Aperture upgrade to go through. New Aperture upgraded the library. The upgrade was not going through (stuck on step 6), so after searching on the web, I started Aperture with Cmd-Option key. I chose the Rebuild library option and that needed upgrade also, and the upgrade happened.

Now, I cannot see images in projects created over the last two years. The images are in Aperture I can tell - because in Library>Projects I can see all the images. However, if I chose a project in left panel, the project has zero images. If I navigate to Library>Photos, then no photos from last two years can be seen. The search box however shows "showing all" photos - so there does not appear to be an obvious filter on.

All processing, creating of previews, thumbnails, face detection post the library build has happened. Since then I have fixed permissions, repaired library, and again rebuilt library.

The images are definitely there - because I can see the images in the referenced location where I stored them.

Here are some snapshots of what I am facing.

One project in Library>Projects

This one has photos. But this is how I view it in the left panel.

There are other threads with this problem, but I thought that if I elaborate, then maybe some of you can pinpoint the specific problem that I am facing.

Thank you!