Issue Mattermost nginx error after changing PHP configuration on another subscription

[onetrackmac]

Server operating system version

Ubuntu 22.04.3 LTS

Plesk version and microupdate number

Version 18.0.57 Update #5,

Hello, I had Mattermost running perfectly on a subscription (mm_server.com) with nginx as the reverse proxy by putting a "location ~ / { ..." directive in the Additional Directives of the domain's Nginx control panel.

I then modified the PHP settings of another subscription (wp_server.com) to accommodate a Wordpress theme. I changed the following settings:

WP Memory Limit
Upload Max Filesize
Max Post Size
Max Execution Size
PHP Max Input Vars
PHP Max Input Time

As soon as I set those parameters, my mattermost server went offline and I cannot get it back online, even after reversing those settings, reinstalling PHP and Nginx, going through all the steps I can find on this forum (and others) about conflicts between PHP an Nginx.
My domain error log only show:

connect() failed (111: Connection refused) while connecting to upstream,

If I remove the "location ~ /" directive I can access the php.info page, but then mattermost shows the index.html page instead of invoking the mattermost api code.

Thanks to whomever can keep me from the nuclear reinstalling the entire server!

 

[mow]

So what is upstream? You'll need to tell us that part of the directive ...
And check the systemd journal for that upstream service.