I observed that on new ObjectDb v.2.6.4.b10 query below causes internal exception
SELECT DISTINCT $1 FROM Pa3DictionaryItem $2 JOIN $2.values $1 WHERE ($2.namespace == 'com.anritsu.pa3.ttcn3' AND $2.key == 'TliEvent' AND $1 != '')
Query above also worked fine on ObjectDb version 2.6.1.b06