Sharing and Permissions from older folders seems to be a problem with El Capitan. I tried to copy a folder from an external drive. That folder was created and copied using Mavericks. It would not copy. Said, I did not have privileges I think was the message. This was all in Finder NOT lightroom.
So, I clicked on the parent folder in question; then did Get Info. In the resulting pane, I changed permissions to "Everyone" . It worked. Then once it was copied, I changed it back! It takes a few minutes to update and warns that it cannot be undone? Not sure what that means since I was able to change Permissions back.
Anyway; back up then try this. Did I say back up first? Yes. YMMV.
Thanks much. I found the permissions area under "Get info" and changed it to the correct user name. I have multiple users - all me and a long story - and that was the source of my problem. Bottom line: this worked. One other thing: don't forget to click the gear at the bottom and select "apply changes." Again, thanks much for this.
Sent from my iPhone
yyep. You're right. I forgot to mention "apply to enclosed item". Glad it worked for you.
ooops. I forgot. Can you mark my reply correct and answered. It helps folks searching for similar.