OS Catalina and iphoto

What have you tried? Have you migrated the iPhoto Library to Photos? Has that failed in some way?

I'll guess you haven't tried that step yetL

Hold down the option (or alt) key and launch Photos. From the resulting menu select 'Choose Library' and point at your iPhoto Library. It will do the rest.

You cannot use iPhoto on Catalina. You would have to downgrade back to your previous system.

But you can open your iPhoto Libraries with Photos for mac to access your photos.

See: How Photos handles content and metadata from iPhoto and Aperture - Apple Support

Double click iPhoto Library to open it in Photos. You should be able to access all photos and albums, the events will appear as albums as well.

There is not update to iPhoto for running under Catalina. You can do one of two things:

1 - create a High Sierra or Mojave boot drive on an external SSD from MacSales.com connected with a SATA to USB 3 adaptor from Benfei:

Boot time is about 45 seconds. With High Sierra I can run iDVD, iMovie 6HD, iPhoto 9.6.1 and many other apps for specific projects.

2 - migrate your iPhoto library to Photos.

Here are some user tips from Photos for Mac  User Tips that will help you in your transition from iPhoto to Photos:

Notes on Migrating an iPhoto Library from iPhoto to Photos for Mac

Moments in Photos are the New Events.

External Editors in Photos Are Here

Photo Editing Extensions for Photos for Mac

Post 9/30/2018 Printing Options for Photos - Apple Community

Ordering Books and Calendars on a Mac that cannot be updated past El Capitan 

Use Project Extensions to order print products in Photos after September 30, 2018 - Apple Support

Create and order print products in Photos with Project Extensions - Apple Support

Although Photos is a bit different in it's GUI it's a much, more powerful image editor.

This worked for me. When I only opened the Photos app, most of the albums were missing. I closed it and opened it again while holding the option key down and chose IPhoto library and now they are all there. I recommend this because it worked for me! Now I am okay about upgrading my system. Thank you!

What is Apple doing to fix this situation?

Apple has replace iPhoto with Photos. Drag your iPhoto library onto the Photos icon either in the Dock or in the Applications folder. Read this Apple document: Notes on Migrating an iPhoto Library from iPhoto to Photos for Mac

First, to be safe backup and rename your current Photos Library. To switch over to Photos, launch Photos with the option key held down. From the resulting dialog, select your iPhoto Library. Photos will create a new Photos Library with the media from your iPhoto Library. Your old iPhotos library will not be affected.

Then you can export all the unmodified originals in the new Photos/iPhotos library. Rename your original Photos library back to what it was and import the originals to your existing Photos Library.

Someone else might chime in with software that will merge your two libraries, but for a one time thing you might want to do it manually

I had the same problem after the upgrade but when I launched the Photos app and went to Albums, then My Albums, there is a folder called iPhoto Events and all my photos in iPhotos are complete.

Try again and post the exact error message, so we have a clue what might be going on on your Mac.

If all fails, revert to Mojave and migrate the iPhoto Library to Photos on a Mac, where you can run iPhoto to prepare the library for the migration.

This will have several advantages:

• You use iPhoto to repair or rebuild the iPhoto Library, if there should be a problem.
• You can remove incompatible media from the iPhoto Library. Catalina does not support all media formats, that you may still have in your iPhoto Library.
• On a system, where yuo can still run iPhoto, you can compare the migrated library to the old iPhoto Library and fix any items, that did not migrate well.

ok, im not sure how the scanning feature helps but all I did was go to search on your Mac, then type in "iPhoto library" and select the library. Open it up and it should open all your files (and open Photo too) and from there you can work on your pics.