jarednova/timber — pull request #296 by andyford (2014-07-16 17:41:56+00:00)
Title: Use WP_SITEURL in 'Timber not activated' error message

This should help if you don't install WP in the default path (and if you've defined the WP_SITEURL constant). Not sure if this is the best way to approach this, but this can at least be a conversation starter.