is_this_user_logged_in() is part of pluggable.php which fires after the plugin loads, hence the problem. I removed the if statement and load both actions et voilà.
Locate the file html-javascript-adder.php which is in the plugins/html-javascript-adder directory.
Replace all instances of
src=”http://localhost/’
with
src=”<?php echo HJA_URL . ‘
these should be on lines 243, 270, 276.
This makes the browser look for the images on the server rather than your computer.