I have been getting that error message when trying to attach files from Dropbox on mobile(Android) devices for a couple of day. Not having any problems with that on my desktop pc. If I can't attach files using Dropbox mobile, Dropbox isn't much use to me. I tried restarting my Android devices but that did not fix it. I don't wish this on anyone, but I hope it's not just me having this issue. Anyone else having that problem lately? Very frustrated with it at this point.