New to this - Errors

[sros]

I wanted to do a simple mirrored sync from one external drive to the other of various image files and a Lightroom catalog. I did it the first time and it went off great. But I didn't save the 'batch' I think is the word. I was trying to use real time sync and didn't understand the command line, so I added a couple files to the original mirrored sync and tried to do it again so I could save it. Now it won't mirror like it did the first time. It says 'Error Code 13: Permission denied [opendir]'
I even deleted all files from drive b to see if I could recreate the simple mirroring and it won't do it anymore.