Iphoto on external drive

I have several iphoto libraries on an external hard drive (Seagate). Now whenever I plug the external drive in it crashes the computer. How do I retrieve the iphoto libraries in order to do a full disk repair on the ext. drive, which will empty it of content? I've tried dragging an iphoto library to pictures, but it didn't complete, and is grayed out. I'm running Catalina on an imac.