ObViously the conversion of # to <> also breaks LLD macro names in triggers.

In Zabbix 2.2.3 I had the following trigger expression (removed uninteresting parts):

{ServerA:agecheck["//1.2.3.4/e$/Backup","8Man.bak"].dayofweek()} > {#DAY_FROM}

In Zabbix 2.4.0 it is now shown as:

{ServerA:agecheck["//1.2.3.4/e$/Backup","8Man.bak"].dayofweek()} > *ERROR*

with status "unknown" and the info field (great thing!) says:

Invalid expression [{42282} > {<>DAY_FROM}]