Uploading of big file size fails: client intended to send too large body

one of our client trying to upload big file size which fails with the following error in

/var/www/vhosts/system/example.com/logs/proxy_error_log file:

Nginx support is enabled on the server:

/usr/local/psa/admin/bin/nginxmng -s
Enabled

We try to adjust client_max_body_size in /etc/nginx/nginx.conf but it has no effect. Actually, Value for client_max_body_size directive is overwritten on domain level and is insufficient.

To resolve this error:

Add the following directives to /usr/local/psa/admin/conf/panel.ini file to customize Plesk defaults:

[webserver]
nginxClientMaxBodySize = 2000m

If there is no /usr/local/psa/admin/conf/panel.ini file, You can create it from the sample file:

cp /usr/local/psa/admin/conf/panel.ini.sample /usr/local/psa/admin/conf/panel.ini

Now rebuild web server configuration files:

plesk sbin httpdmng --reconfigure-all

Please note: Execution of the above command could cause a significant downtime to the hosted websites if there are a big number of them. Perform such action during the maintenance timeframe
Adjust settings of PHP handler assigned to the domain. Go to Plesk > Tools & Settings > PHP Settings > X.X.XX FPM application in php.ini tab and adjust the following parameters:

post_max_size 2000m

upload_max_filesize 2000m

max_file_uploads 100

That’s all.