Plugins missing

When I updated to wordpress 3.8.1 all of my plugins disappeared. Now when I try to reinstall them this happens:

Installing Plugin: The Events Calendar 3.3.1
Downloading install package from https://downloads.wordpress.org/plugin/the-events-calendar.3.3.1.zip…

Unpacking the package…

Installing the plugin…

Destination folder already exists. /home/luumsorg/public_html/wp-content/plugins/the-events-calendar/

Plugin install failed.

Any help as to how I can rectify this and get my plugins back? The website doesn’t really function without them.