The world most popular WordPress CMS system website is currently experiencing issue.
If you are a WordPress admin, and would like to add plugin, or Add theme, now is not the time. Lets give them some time to resolve the issue, and they will be all back soon, as always.
More information can be found here: https://status.wordpress.org/
Latest update as of 5 August 11am (SGT), the issue has been resolved.