I can't copy my iPhoto library to an external HD

[julienlrck]

Just after transferring my itunes library to my HD I've tried to transfer my iPhoto library but as the file 'iPhoto Library' is getting copied about a 100MB's in it stops and says "The operation can't be completed because the item "iPhoto Library" is in use." I've tried closing every application on my computer apart from Finder but it still comes up with the same message. I use an OSX Yosemite 10.10.1 macbook pro. Any help would be appreciated thanks.

 

[Partron22]

Use Force Quit (cmd opt esc ->dialog) to restart Finder. You've probably got some file or other in there that the Finder thinks Preview is using.
Reboot, without auto-restarting Apps, should work as well.