Permission denied /dev/null error when Configuring gitlab Mattermost on Omnibus installation

I followed the instructions here https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/doc/gitlab-mattermost/README.md
I’m using GitLab v 10.6.3

Mattermost and Gitlab are on the same server so I just enable

mattermost_external_url ‘http://mattermost.mydomain.com

and run gitlab-ctl reconfigure which completes successfully, but when I visit the url it does not load mattermost.
Gitlab has well has an issue I can login and access most this except my projects, when a click on a project link I get a gitlab error 500. If I dissable mattermost everything works ok.

Upon checking logs I can see

‘mattermost log’
[2018/04/05 08:58:07 EAT] [EROR] unable to start plugin: jira: timed out waiting for plugin
[2018/04/05 09:14:31 EAT] [EROR] unable to start plugin: jira: timed out waiting for plugin
[2018/04/05 09:14:34 EAT] [EROR] unable to start plugin: jira: timed out waiting for plugin
[2018/04/05 09:14:38 EAT] [EROR] unable to start plugin: jira: timed out waiting for plugin

‘current file’
2018-04-05_06:14:35.07573 open /dev/null: permission denied
2018-04-05_06:14:38.03203 [2018/04/05 09:14:38 EAT] [EROR] unable to start plugin: jira: timed out waiting for plugin
2018-04-05_06:14:38.03639 [2018/04/05 09:14:38 EAT] [INFO] Starting workers