On the smart class parameters view, when i search for a parameter with a simple string, for example just typing "host" in the search field, I've got a sql error :

Mysql2::Error: Unknown column 'lookup_values.value' in 'where clause': SELECT `lookup_keys`.`puppetclass_id` FROM `lookup_keys` WHERE `lookup_keys`.`type` IN ('PuppetclassLookupKey') AND ((`lookup_keys`.`key` LIKE '%host%' OR `lookup_values`.`value` LIKE '%host%' OR `puppetclasses`.`name` LIKE '%host%')) ORDER BY `lookup_keys`.`key` ASC LIMIT 20 OFFSET 0

The error seems to be that the where clause uses fields from the tables lookup_values and puppetclasses but they are not present in the FROM.
I tested the query after adding the tables in the FROM, but it generates a temporary table which fullfills the /tmp and crashes