Our Homeschooling Co-Op has a dropbox page with files for pictures. There has been a link put into our weekly announcement emails for people to put pictures into the Co-Op picture files for others to see. This doesn't seem to be working the way that we thought it would. It seems that we are unable to upload pictures into the files. I was able to upload some to a file of which I was personally invited to use. Do we have to personally invite everyone?