Error on export to external hard drive

[NK]

Hi there,

Most of my export has gone smoothly until the very end - where I get this message:

Reading iPhoto database from /Users/Nikki/Pictures/iPhoto Library...

Version 8.1.2 library with 29802 images

Phoshare.py --export "/Volumes/Nikki - 500GB/phoshare backup - sept 24: 2014" --iphoto "~/Pictures/iPhoto Library" --events "." --foldertemplate "{yyyy}/{mm}/{dd} {name}" --nametemplate "{title}" --captiontemplate "{description}" --originals --iptcall --gps

Scanning iPhoto data for photos to export...

Scanning existing files in export folder...

Error: [Errno 13] Permission denied: '/Volumes/Nikki - 500GB/phoshare backup - sept 24: 2014'

Traceback (most recent call last):

  File "/Users/Nikki/Downloads/Phoshare.app/Contents/Resources/lib/python2.7/phoshare/phoshare_ui.py", line 986, in export_thread

  File "/Users/Nikki/Downloads/Phoshare.app/Contents/Resources/lib/python2.7/phoshare/phoshare_main.py", line 732, in export_iphoto

  File "/Users/Nikki/Downloads/Phoshare.app/Contents/Resources/lib/python2.7/phoshare/phoshare_main.py", line 646, in load_album

  File "os.pyc", line 157, in makedirs

OSError: [Errno 13] Permission denied: '/Volumes/Nikki - 500GB/phoshare backup - sept 24: 2014'

Any suggestions?