Thread:Project:Support desk/Failed to set the local repo temp zone container to be private/reply (3)

it creates an .htaccess with only this line:

Deny from all

Note that it will create it using the user account running the upgrade script. If you're running the web updater, the error shouldn't happen, and if it does, then the web server doesn't have permissions to write to that folder (which may result in errors when you upload a file). If you're running the update.php maintenance script, then it may fail because of the same (permissions for webserver, not for the user running the script).