A bunch of big updates for Basecamp 3
Jason Fried

I’m a new user and had very little time to use BC2. Since the upgrade to BC3, the files I upload appear ‘broken’ in my Windows installation. There is no preview and when I try to download the file, there is no file extension! I found that I can add the file extension manually while saving it, but that’s really not a solution. 
In my Android Basecamp 3 it’s all fine. I see the preview and can open and save the files normally
Thanks in advance!