This is NOT a bug in rawtherapee! You installed a version of rawtherapee from a ppa (-> rawtherapee 4.2-4dhor~trusty). Purge rawtherapee fist and install it again.
This is NOT a bug in rawtherapee! You installed a version of rawtherapee from a ppa (-> rawtherapee 4.2-4dhor~trusty). Purge rawtherapee fist and install it again.