React Router BrowserRouter leads to "404 Not Found - nginx " error when going to subpage directly without through a home-page click

The problem is that nginx doesn't know what to do with /signin. You need to change your nginx config (usually in /etc/nginx/conf.d/) to serve your index.html regardless of the route. Here is a sample nginx config that might help:

server {  listen 80 default_server;  server_name /var/www/example.com;  root /var/www/example.com;  index index.html index.htm;        location ~* \.(?:manifest|appcache|html?|xml|json)$ {    expires -1;    # access_log logs/static.log; # I don't usually include a static log  }  location ~* \.(?:css|js)$ {    try_files $uri =404;    expires 1y;    access_log off;    add_header Cache-Control "public";  }  # Any route containing a file extension (e.g. /devicesfile.js)  location ~ ^.+\..+$ {    try_files $uri =404;  }  # Any route that doesn't have a file extension (e.g. /devices)  location / {    try_files $uri $uri/ /index.html;  }}

Just simply add try_files $uri $uri/ /index.html; to location / block in NGINX configuration file like this:

server {   listen       80;   server_name  localhost;   location / {       root   /build;       index  index.html;       try_files $uri $uri/ /index.html;   }}

On location add this

location / {try_files $uri /index.html;}