Cannot update Craft, only download the zip Recently I cannot update Craft on a server. From versions 2.6.2778 and 2.6.2779. I only can download the zip to install it myself. What could be wrong here? 
Thanks in advance.

PHP: 5.6.16-1byte1

Alert on iconv (older version)
You can do manual installs easily, all you really need it's the app folder inside the craft folder. but don't just replace it.
I would rename the new app folder to something like "app-new" move it next to the other app folder inside craft folder. once it is all done copying. I would rename the "app" folder into "app-old" and rename the "app-new" into "app" again. Then go to your admin URL and craft should do the automatic database changes that it needs. It has worked for me in the past and it's quick and easy and less error prone.