Add New Plugin always shows error

THe error is “An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration. If you continue to have problems, please try the support forums”

The most likely issue is the webserver can’t connect to the internet or is unable to connect securely. If you have error logs on the server, check them for more detailed information as to what has failed.

try MANUAL updating to 4.2.1. Download a fresh copy of the WordPress .zip file to your computer, unzip it, and use that to copy up all files and folders EXCEPT the wp-config.php file and the /wp-content/ directory. You may need to delete the old copies of files & folder on your server before uploading the new ones. Read the Manual Update directions first.
– If you haven’t already done, always backup everything (including your database) before doing any actions, just in case something really goes wrong.