I am getting the same thing. I can't upgrade from WebGUI (fails) and then when I try to do CLI I get the following error:
ubnt@ubnt:~$add system image http://dl.ubnt.com/firmwares/edgemax/v1.8.5/ER-e100.v1.8.5.4884695.tar
Trying to get upgrade file from http://dl.ubnt.com/firmwares/edgemax/v1.8.5/ER-e100.v1.8.5.4884695.tar
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
85 82.7M 85 70.5M 0 0 10.6M 0 0:00:07 0:00:06 0:00:01 12.6M
curl: (23) Failed writing body (846 != 16384)
Unable to get upgrade file from http://dl.ubnt.com/firmwares/edgemax/v1.8.5/ER-e100.v1.8.5.4884695.tar
ubnt@ubnt:~$
