Cannot get into iphoto

Question

Update graded my iMac back in mid May 2012 and was able to get into iPhoto just fine.  Now I cannot not as it wants me to upgrade and then tells me that my library will be unreadable by prevision version.  Yesterday I had to reload my HP 6500 printer, is that my problem?

Answer 1

What do you mean by won't open?  Does it just sit there in the Dock and bounce up and down without a window opening? What?
Try this:  launch iPhoto with the Option key held down and try to create a new, test library. If you can  import some photos and then close and open iPhoto to check if the same problem persists. If you can't create and use a new library then try the following: make a temporary, backup copy (if you don't already have a backup copy) of the library and try the following:
1 - delete the iPhoto preference file, com.apple.iPhoto.plist, that resides in your
     User/Home()/Library/ Preferences folder.
2 - delete iPhoto's cache file, Cache.db, that is located in your
     User/Home()/Library/Caches/com.apple.iPhoto folder.
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3 - launch iPhoto and try again.
NOTE: If you're moved your library from its default location in your Home/Pictures folder you will have to point iPhoto to its new location when you next open iPhoto by holding down the Option key when launching iPhoto.  You'll also have to reset the iPhoto's various preferences.
If you can create and use a new library then the culprit is your current library.  If that's the case make a temporary, backup copy (select the library and type Command+D) and  apply the two fixes below in order as needed:
Fix #1
Launch iPhoto with the Command+Option keys held down and rebuild the library.
Since only one option can be run at a time start with Option #1, followed by #3 and then #4.
Fix #2
Using iPhoto Library Manager  to Rebuild Your iPhoto Library
Download iPhoto Library Manager and launch.
Click on the Add Library button, navigate to your Home/Pictures folder and select your iPhoto Library folder.
Now that the library is listed in the left hand pane of iPLM, click on your library and go to the File ➙ Rebuild Library menu option
In the next  window name the new library and select the location you want it to be placed.
Click on the Create button.
Note: This creates a new library based on the LIbraryData.xml file in the library and will recover Events, Albums, keywords, titles and comments but not books, calendars or slideshows. The original library will be left untouched for further attempts at fixing the problem or in case the rebuilt library is not satisfactory.