I tried to upgrade my OS to Windows 10. It didn't work out but that's another story. When I opened my LR5 I couldn't find my photos. My LR catalogue is on my c: drive and my photos are on an external drive. Any suggestions?
I would suggest you to reconnect the images in Lightroom to the original images from your external driver.
Please have a look at the following article : https://helpx.adobe.com/lightroom/help/locate-missing-photos.html
Please let us know if it helps.
Retrieving data ...