The error looks like Ngnix throwing this error.
Use nano text editor:
$ sudo nano /etc/nginx/nginx.conf
Must be run as root:
vi /usr/local/nginx/conf/nginx.conf
Add the following line to http or server or location context to increase the size limit in nginx.conf, enter:
set client body size to 2M
client_max_body_size 2M;
The client_max_body_size directive assigns the maximum accepted body size of client request, indicated by the line Content-Length in the header of request. If size is greater the given one, then the client gets the error “Request Entity Too Large” (413).
Save and close the file. Reload the nginx webserver, enter:
/usr/local/nginx/sbin/nginx -s reload
Use nginx itself to reload it:
/sbin/nginx -s reload
For RHEL/CentOS/Debian/Ubuntu Linux, try:
service nginx reload
If you are using systemd based system run:
$ sudo systemctl reload nginx.service