I am not able to use the remote install and updates page to update JReviews or install add-ons
This problem typically happens on localhost installations, but in a few rare cases also on some live hosting environments. The remote install & updates functionality requires making a connection with our server first to retrieve the file manifest ( the list of all available packages ) and later to retrieve the actual packages. All communications are secure and performed using an SSL connection. The problem occurs when a server has outdated certificates. You can read more about this issue here.
To fix the problem download an up to date CA root certificate bundle from http://curl.haxx.se/docs/caextract.html
Then set a path to it in your php.ini file, e.g. on Windows: