Bad response from token request after team creation auth

Well, I updated gitlab and mattermost to latest 8.5 / 2.0, but i still can't create a team. Nothing changed, same error and nothing on logs.

Tried EnableInsecureOutgoingConnections : true too.

Gonna raise an issue in the repo and hope for some solution there.

Thanks again for the help jwilander

Edit :

Posting my apache conf (from my vhost on plesk), in case someone sees something wrong :

mattermost.mydomain.com

ServerName mattermost.mydomain.com
ServerAlias mattermost.mydomain.com

#DocumentRoot /opt/gitlab/embedded/service/mattermost/web

ProxyPreserveHost On
RewriteEngine On

RewriteCond %{REQUEST_URI}  ^/api/v1/websocket    [NC,OR]
RewriteCond %{HTTP:UPGRADE} ^WebSocket$           [NC,OR]
RewriteCond %{HTTP:CONNECTION} ^Upgrade$          [NC]
RewriteRule .* ws://127.0.0.1:8065%{REQUEST_URI}  [P,QSA,L]

RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f
RewriteRule .* http://127.0.0.1:8065%{REQUEST_URI} [P,QSA,L]

# Be sure to uncomment the next 2 lines if https is used
# RequestHeader set X-Forwarded-Proto "https"
# Header set Strict-Transport-Security "max-age=31536000; includeSubDomains"

# Prevent apache from sending incorrect 304 status updates
RequestHeader unset If-Modified-Since
RequestHeader unset If-None-Match

<Location /api/v1/websocket>
    Require all granted
    ProxyPassReverse ws://127.0.0.1:8065/api/vi/websocket
    ProxyPassReverseCookieDomain 127.0.0.1 mattermost.mydomain.com
</Location>

<Location />
    Require all granted
    ProxyPassReverse http://127.0.0.1:8065/
    ProxyPassReverseCookieDomain 127.0.0.1 mattermost.mydomain.com
</Location>

gitlab.mydomain.com

ServerName gitlab.mydomain.com
ServerSignature Off

ProxyPreserveHost On

# Ensure that encoded slashes are not decoded but left in their encoded state.
# http://doc.gitlab.com/ce/api/projects.html#get-single-project
AllowEncodedSlashes NoDecode

<Location />
    # New authorization commands for apache 2.4 and up
    # http://httpd.apache.org/docs/2.4/upgrading.html#access
    Require all granted

    #Allow forwarding to gitlab-workhorse
    ProxyPassReverse http://127.0.0.1:8181
    ProxyPassReverse http://gitlab.mydomain.com/
</Location>

# Apache equivalent of nginx try files
# http://serverfault.com/questions/290784/what-is-apaches-equivalent-of-nginxs-try-files
# http://stackoverflow.com/questions/10954516/apache2-proxypass-for-rails-app-gitlab
RewriteEngine on

#Forward these requests to gitlab-workhorse
RewriteRule .* http://127.0.0.1:8181%{REQUEST_URI} [P,QSA]

# needed for downloading attachments
DocumentRoot /opt/gitlab/embedded/service/gitlab-rails/public

#Set up apache error documents, if back end goes down (i.e. 503 error) then a maintenance/deploy page is thrown up.
ErrorDocument 404 /404.html
ErrorDocument 422 /422.html
ErrorDocument 500 /500.html
ErrorDocument 503 /deploy.html

# It is assumed that the log directory is in /var/log/httpd.
# For Debian distributions you might want to change this to
# /var/log/apache2.
LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b" common_forwarded
ErrorLog /var/log/httpd/gitlab.mydomain.com_error.log
CustomLog /var/log/httpd/gitlab.mydomain.com_forwarded.log common_forwarded
CustomLog /var/log/httpd/gitlab.mydomain.com_access.log combined env=!dontlog
CustomLog /var/log/httpd/gitlab.mydomain.com.log combined