if file size is to small
This might just be the place you're looking for. By default NGINX comes with a rather small upload limit for mainly security and disk usage reasons. However, this is a simple to change issue for all. Follow the below steps for a quick fix on this issue.
Open The Config File
By default there will be an NGINX config file located at
/etc/nginx/nginx.conf
Open this file via SMTP or the nano command
Applying The Fix
Now this file is structured in a particular way. So we can't go around placing this anywhere.
In the HTTP block (after http {) we want to place our line.
client_max_body_size 1000M; # This will increase the limit to 1GB. Measured in MB.
Keep note that setting it to 0 disables checking of client request body size.
(client_max_body_size 0; # Disables checking client body size)