Blank System Status screen and invalid [civicrm.files] URL variable on fresh CiviCRM v.4.7.30 and WordPress v.4.9.4 install
The issue is that the file structure you are using is not accounted for in the installer.

We've covered the standard directory structures and detect them, however there are some use cases that we have not been able to both detect and set programmatically.  In these cases, you will need to override the values.  

In your case you needed to override the URLs as the [civicrm.files] URL is appending /home/myorganization/www/sites/staging/crm.myorganization.org to the URL.   

I have seen this before (mostly with symlinks or if both WP is installed in it's own directory AND wp-content has been moved).   Can you let us know who your host is and confirm your configuration?