I have built a site that worked fine on my local development machine (MacBook Pro) but the admin panel would hang on the loading screen in the hosted site. The reason for the failure was because it was failing to find the .js files in the assets folder. They were there but weren't being seen.
In the assets folder, there is a .htaccess file with a single line:
php_flag engine off
Deleting this file seems to have fixed the problem.
This file is obviously there for a reason. Can anyone offer a comment?