Ratel crashes with a blank screen when clicking schema Predicate or Samples & Statistics

No dgraph return successful result to the following query.

{
        samples(func: has(<post-attachment>), first: 10) {
            uid
            expand(_all_) {
              uid
              expand(_all_)
            }
        }
    }

but parsing fails. I don’t know exactly what’s happening on react side.

I think it is related with expanded edges.
React part does not expect an inner object within samples.

Reproduction scenario might be this (not tested):
create some records with edges.
then click the edge in the predicates page.