I moved masters to an external HD and would like to move them back

First how did you move them? In Aperture using Relocate Masters or with the Finder? Were the masters already referenced when you moved them?

If you moved with the Finder, which is what it sounds like you did, you will need to use Locate Referenced Files.. to reconnect them to the library.

If you did some other operation post back and explain what you did.

regards

When you're in the Referenced Files in Selection window you need to select one file from the upper pane and find it in the lower pane then the reconnect button should be active.

No, once you reconnect one image the reconnect all button should become active and you can use that. Depending on a few factors it may reconnect them all in one shot or you may have to repeat the cycle a few times (select one, reconnect it, reconnect all)

Is it possible that your Masters were "connected" all the time? It seems that Frank understood your question to be "How do I reconnect the Images in my Library with their Missing Masters that are located on an external drive?", where what you were perhaps wanting to ask was "How do I move Referenced Masters back into my Library?" The difference is whether the Masters in question were Missing (no longer properly linked to Images in the Library). The mis-reading seems to have hinged on "reunite".

I mention this because though you have resolved your issue, it still appears to be unclear what the issue was.

This would explain why you couldn't reconnect your Masters using "File→Locate Referenced Masters": there were no Missing Masters. It also explains why "File→Consolidate Masters" worked.

That it would explain it doesn't make it correct; it just makes it more likely than anything else I can come up with. Could you confirm? Thanks.

I believe Kirby's analysis is correct. Looking back at your fist post I think the use of the word 'reunite' threw me off. I read is as reconnect.

Glad you got it sorted out anyway,

regards