photos app in my mac is not able to open the iPhoto library from my external hard disk.
I am using iMac (21.5-inch, Late 2013) OS 10.10.3. i have 2 iPhoto library one on my Mac HD and the other on my External HD which i primarily use and which has all the latest photos in it. Now with the new update to photos app in Mac i am not able to open the iPhoto library from my external HD. I get the following error message please help.
iMac, OS X Yosemite (10.10.3), null