No, these is no need to check “always loaded in memory” at this point.
Hum, if ressources are good, then something else is happening.
Can you preview your game over wifi (it will start a local webserver on your computer), and open the url generated in your web browser (chrome or firefox) ?
Does the browser make black screen too ? If yes, then open developper console (ctrl+shift+i) and look for errors.