can't open i photo since installing yosimite 10.10 even after installing photo library upgrade

Downloading the iPhoto library upgrader is not the deal - you also have to run it - it is located in the utilities folder in the applications folder - double click on it and after it completes then launch iphoto to complete the upgrade - this is only required if your old version of iPhoto is iPhoto '08 (version 7.x.x) or older

LN

even after installing photo library upgrade

Have you upgraded to iPhoto 9.6? Only version 9.6 will run on Yosemite.

Great

You are welcome

LN

thank you

You are welcome

LN

Here's a little something you can try!!! 🙂

Go to your applications folder and find iPhoto. Right-click on it and select "Show Package Contents". Now inside that, go to Contents>MacOS and you should find a few terminal files. Open "iPhoto" in terminal stay on terminal and wait for it to do it's magic. iPhoto will eventually open like normal (YAY!) and you can find your photos (well, it worked for me, anyway so hopefully). Don't close terminal, or iPhoto will quit. When you want to quit out, quit out of iPhoto normally and then quit out of terminal.

HOPE THIS WORKS YAY!!!

This has nothing whatever to do with the question asked and is potentially quite dangerous to the Library and its contents.

Don't do this too much bc it isn't good for your mac sozzy i forgot to say but it will at least backup ur photos