Steps to reproduce:
-> Create an JMX Discovery;
-> Add a Javascript Pre Processing to add one more LLD Macro to the JSON;
-> Itens e triggers created by this discovery don't find this new LLD Macro and the LLD Macro itself is add to items key/name, so, the name is show up as "...

...";

Workaround:
-> Use Java Gateway 4.4 or up to be possible to use item "jmx.get";
-> Pre-processing is fired when this item is used, so we can transform the result to a JSON accepted by the LLD Rule;