external device backup query
hey, i took backup on external storage "Seagate", now i am not able to open photos on it, it says formate not supported by photo library.. what should i do now? how to make sure whether backup is done properly on external device? will i be able to open picture through external device if i delete photos from my macbook... please help.
thanks in advance
MacBook Air, macOS Sierra (10.12.6)