Errors with Jetpack Photon active

When I activate Jetpack Photon on my website, the Recent Custom Posts plugin stops working. In my error log I see the following:

[Fri Aug 21 15:16:33.672864 2015] [:error] [pid 16644] PHP Warning: sprintf(): Too few arguments in /wp-content/plugins/recent_custom_post_type/recent-custom-post-type.php on line 345

Any suggestions? I'd like to use Jetpack Photon. Feel free to troubleshoot on my website: