iPhoto library stored externally and after upgrade doesn't want to open file
I recently needed to free up some hard disk space on my Macbook and exported my iphoto library on to my external hard drive. This allowed me to install OS Yosemite and update all my software apps and programs including iphoto. However after the iPhoto upgrade, I get the succession of following messages when trying to open up my iphoto library from the external drive:
1. The photo library need to be upgraded to work with this version of iPhoto - Click Upgrade
- After I click upgrade I get a second message...
2. There is a problem accessing one or more files in you iPhoto library. Do you want iPhoto to repair permissions for this library for you? - Click repair
- After clicking repair third and final message appears before iPhoto automatically quits..
3. Warning: The library could not be opened because the file system of the library's volume is unsupported.
If any once can help with advice on how to restore my iPhoto library please advise.
MacBook, iOS 8.2