I just upgraded from 7.0.2 to 7.1, and thought I would point out a problem -- hope it helps others.
The process updates files or creates files in the /languages and languages/english folders, yet the permissions on my site were not set to allow it.
I only recently installed 7.0.2 from scratch and followed the install instructions. However, in the section "Set File & Directory Permissions", it does NOT specify that these folders or files' permissions should be changed.
It caused me a bit of head-scratching, but once I set the permissions to enable write access, the upgrade continued.
It would be nice if the initial install instructions, or else the upgrade instructions, would note the requirement to set the permissions for that branch of folders and files.
