Adding a new protected machine results in a blank screen

Symptom

When clicking +New Machine to add a new protected machine, the new machine is not added, and instead the user is presented with a blank screen.

Additionally, the following error may be found in Nginx logs :

 upstream sent invalid chunked response while reading upstream 

Cause

This issue is caused by a running Nginx reverse proxy on the Backup Manager system.
By default, Nginx uses Http 1.0 when functioning as a reverse proxy. The "Transfer-Encoding: chunked" response in the R1Soft Backup Manager headers, requires Http 1.1 when no chunked data is sent.

Resolution

Configuring Nginx to use Http 1.1, by adding the lines below, resolves this issue.

 proxy_http_version 1.1;
 proxy_set_header Connection ""; 

Depending on how Nginx is being used, the configuration change may be added to one of the following conf files:

Global Configuration :

Add the following lines to the http{} section of the primary configuration file : /etc/nginx/nginx.conf

 # Chunked response handling   
 proxy_http_version 1.1;
 proxy_set_header Connection ""; 

Server Block Configuration (installed from the official Nginx repository) :

Add the following lines to the site config of the virtual host, located here : /etc/nginx/conf.d/

Example:

  # R1Soft
 location / {
    proxy_pass http://127.0.0.1:8080;
    ...
    proxy_http_version 1.1;
    proxy_set_header Connection "";
 } 

Server Block Configuration (installed from Debian or Ubuntu Repositories) :

Add the following lines to the site config of the virtual host, located here : /etc/nginx/sites-available/
(configs created in this folder are typically enabled by symlinking to /etc/nginx/sites-enabled/ )