(104)Connection reset by peer: [client ip:57893] mod_fcgid: error reading data from FastCGI server

This is since applying a letsencrypt cert, worked fine on HTTP. Other VPS's on the same box run letsencrypt certs no problem.

[Thu Dec 07 02:00:45.315314 2017] [fcgid:warn] [pid 7100] (104)Connection reset by peer: [client ip:57893] mod_fcgid: error reading data from FastCGI server [Thu Dec 07 02:00:45.315360 2017] [core:error] [pid 7100] [client ip:57893] End of script output before headers: index.php

This is running on a Ubuntu 16.04 AWS box

Any help is appreciated,