Sorry for the confusion I might have caused to you, I forgot to check the stack itself. Indeed, nginx is not being included (now I understand your initial frustration a lot better).
In the case of our stack, instead of using NGINX as proxy, we use Apache. It seems that Discourse developers did their application thinking on NGINX exclusively, hence that debug texts. In order to solve this, you only have to "port" the fix suggested to Apache.
Can you try adding this line to your apache config file (
/opt/bitnami/apache2/conf/httpd.conf) and restarting your servers? (
sudo /opt/bitnami/ctlscript.sh restart).
The line is
LimitRequestBody 102400, where 102400 is the size in bytes you want to allow. (Bear in mind that 1024 bytes are a kilobyte, and not 1000)
Please don't hesitate to write us back if you found anything unclear.