While you can use the Emulator (in Box or via CLI) to develop or adjust your player, some of the features might not behave as you would expect. One of them is a non-SSL request from your Applet.
On real devices like Samsung SSP, LG webOS,… and others it is possible to call unsecured non-SSL domains via JS/Ajax. Unfortunately, this is not possible within the Emulator due to it's web nature.
Why it's happening
This is mainly because of the Chrome browser limitation as Chrome does not support unsecured call on SSL enabled domain.
How to Resolve
Option A) Setup a reverse proxy with valid SSL certificate or use Let's Encrypt for your dev environment
Option B) To bypass this limitation try to change the URL of the emulator from https to plain http. With this change you should be able to continue developing your Applet.