What does this error message mean?

Hi I’ve extracted the translator files from the zip, transfered them into my wp content > plugin files on FTP but when I activate the plugin in WP I get the following message

Unable to complete Global Translator initialization. Please make writable and readable the following directory:

* /var/www/vhosts/ardleighbedandbreakfast.co.uk/httpdocs/wp-content/plugins/global-translator

Please help

Thanks