Lost Photos

I think you have created a new library for the new photos and the old library is likely somewhere on your Mac unless you reformatted the hard drive. Were the old photos in an iPhoto library? Meaning were you storing them in iPhoto or Aperture before your update. Also, did you back up your Mac before you updated the OS as is suggested?

in Finder, turn on Sidebar if it is not already on (Finder Menu > View > Show Sidebar). Open the Pictures folder. Do you see more than one library in there? One should be Photos Library.photoslibrary by default, though it could be another name. It will show a recent date if you right click and choose Get Info. Do you see another file similarly name iPhoto library?

This means you need to update the library before importing to Photos. Find your iPhotos app in Finder under Applications and move it to the trash. Then look in the "Purchases" tab of the App Store application to find iPhoto 9.6.1. Download and install that and open the library you found with iPhoto 9.6.1. This will update the library. Then you can close iPhoto and follow these instructions to add a second library to your new Photos library.

http://www.imore.com/how-import-your-iphoto-library-photos-os-x

I thought you found that library and the system told you the iPhoto library was too old. So you are still looking for your older library? If so, the see my comment about Finder 5 messages above. If you found the iCloud library and importing gave you an message the library was out of date follow the message 2 above.

Sorry but we can not see you and to help you you have to provide clear information and answer questions

Like these three questions for example

1 - Were the old photos in an iPhoto library?

2 -Meaning were you storing them in iPhoto or Aperture before your update.

3 - Also, did you back up your Mac before you updated the OS as is suggested?

The most basic answer with you providing no information is for you to drag your iphoto library to the Photos icon in the Dock and migrate it to Photos - It sounds like you did not ever get a good migration and so started off with an new, empty library

And three more questions - what version of Photos do you have? Of the OS? Of iPhoto?

LN

How did you find your photos? I have been trying and I can't find my photos