When trying to attach a small zip file, I have the following error message

Copy failed
Failed to upload file 'gender_support_int_cb140.zip': Could not move file into /home/joomlapolis824/public_html/media/kunena/attachments/167550/gender_support_int_cb140.zip

Post/Topic is www.joomlapolis.com/forum/146-general/157087-automatic-gender-specific-avatar-cb-14#157087

What can I do or try to do?