Can not activate plugin

What version of PHP are you running? There is an issue with some version 5.4, see https://wordpress.org/support/topic/error-after-update-parse-user-agentphp?replies=16

Can you try upgrading to a newer version of PHP?

I’ve submitted a patch back to the library we use that is producing the error to remove the anonymous function usage (which is the problem) but it hasn’t been updated yet.

Are you sure? Most hosting providers support 5.5 or 5.6.

If not you can grab an older version of the parser library here: http://plugins.svn.wordpress.org/wp-statistics/tags/7.4/includes/functions/parse-user-agent.php

but you’ll have to keep a copy handy any time there’s an update.

Unfortunately it’s not that easy as it appears to be a combination of version plus extensions.

I’m hoping my patch to the library will be accepted soon.