Querying a self-reference

Hey Team, I got a problem with a self-reference query. The query that should provide all children (subcomponents) does not retrieve anything. When I try to debug the microflow I get an error (error message is included below).  Despite of this error  I am still able to run the app. The added breakpoint to the query  does not its job and is crossed over. Does anyone has an idea what the problem could be? Thanks in advance.
1 answers

Is there an aggregate list function after the retrieve?

If so mendix will optimize the database query and not actually retrieve the list but do a count/sum etc directly from the database

This means you won't be able to set your breakpoint on the retrieve. But you'll have to set it on the aggregate list action.

The error message text could be better in these cases.