All the files I upload to the tree.io tickets, projects, etc cannot be downloaded, 
I am getting a 404 error. 
I am running tree.io in a cantos 6 box.
any ideas to get this working please ?
after sometime found a solution for this.

i had to define the MEDIA_ROOT as an absolute URL in the settings.py
when i went to static/media there was no folder called attachments, i had to make one and give it the correct permissions for python can write to that folder. 

this worked for me.
cant download files uploaded tree.io