TypeError: Drupal\stage_file_proxy\EventSubscriber\StageFileProxySubscriber::createProxyHeadersArray(): Argument #1 ($headers_string) must be of type string, null given, called in /app/docroot/modules/contrib/stage_file_proxy/src/EventSubscriber/StageFile

Why would the headers be empty?

I'm getting the same issue. This change seems to fix it but I'm wondering if I'm missing something I should have in the config?

`stage_file_proxy.settings.yml`

hotlink: false
origin: ''
origin_dir: ''
use_imagecache_root: true
proxy_headers: ''
verify: true
excluded_extensions: ''