Jira issue originally created by user cloun:
I made mapping field in base class to DiscriminatorColumn and because of this EntityRepository->find($id) returned object with parent type (although this row corresponded to child type).
I performed deep debugging and found out the reason in the StandardEntityPersister->_processSqlResultInheritanceAware method.
May be if explicity write about this it will save the time of future users..
Comment created by @beberlei:
Added additional validations for duplicate field/association names and column names, in combination with the discriminator column name also.
Issue was closed with resolution "Fixed"