I've tried to include WPML_DO_NOT_LOAD_EMBEDDED_TM in wp-config.php and the effect is the same: translation manager is disabled but errors are logged. I'd need the plugin you provided in late ticket.
I need the mu-plugin you created. You should not hide the URL. I'm creating a 2nd duplicate of the initial issue just because I cannot access the hidden link!!
Any external URLs that are not pointing to tickets from our site or WPML documentation will automatically be hidden for anyone else except the user that opened the ticket and the supporter.