I include my CSS files in the header:

In the S3 interface under Properties–>Metadata–>

Permissions are granted to Everyone with Open/Download

Still not working.

The problem is determining the path to the static content of the application (it depends on path the application starts olso)

Solutions are:

1. Start application from root application path

   example: ApplicationName path=/home/ec2-user/site then need
   

   Default

   cd /home/ec2-user/site && ./ApplicationName

   1 2	cd /home/ec2-user/site && ./ApplicationName

2. Configure path for method .UseWebRoot(path_to_static_content)