Absinthe compilation error

== Compilation error in file lib/app/schema.ex ==
** (KeyError) key :location not found in: nil. If you are using the dot syntax, such as map.field, make sure the left-hand side of the dot is a map
    (absinthe 1.7.1) lib/absinthe/phase/schema/validation/type_references_exist.ex:142: Absinthe.Phase.Schema.Validation.TypeReferencesExist.error/2
    (absinthe 1.7.1) lib/absinthe/phase/schema/validation/type_references_exist.ex:114: Absinthe.Phase.Schema.Validation.TypeReferencesExist.check_or_error/4
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:16: anonymous fn/3 in Absinthe.Blueprint.Transform.prewalk/2
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:117: Absinthe.Blueprint.Transform.walk/4
    (elixir 1.14.5) lib/enum.ex:1780: Enum."-map_reduce/3-lists^mapfoldl/2-0-"/3
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:147: anonymous fn/4 in Absinthe.Blueprint.Transform.walk_children/5
    (elixir 1.14.5) lib/enum.ex:2468: Enum."-reduce/3-lists^foldl/2-0-"/3
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:122: Absinthe.Blueprint.Transform.walk/4
make: *** [build] Error 1

== Compilation error in file lib/app/schema.ex ==
** (KeyError) key :location not found in: nil. If you are using the dot syntax, such as map.field, make sure the left-hand side of the dot is a map
    (absinthe 1.7.1) lib/absinthe/phase/schema/validation/type_references_exist.ex:142: Absinthe.Phase.Schema.Validation.TypeReferencesExist.error/2
    (absinthe 1.7.1) lib/absinthe/phase/schema/validation/type_references_exist.ex:114: Absinthe.Phase.Schema.Validation.TypeReferencesExist.check_or_error/4
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:16: anonymous fn/3 in Absinthe.Blueprint.Transform.prewalk/2
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:117: Absinthe.Blueprint.Transform.walk/4
    (elixir 1.14.5) lib/enum.ex:1780: Enum."-map_reduce/3-lists^mapfoldl/2-0-"/3
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:147: anonymous fn/4 in Absinthe.Blueprint.Transform.walk_children/5
    (elixir 1.14.5) lib/enum.ex:2468: Enum."-reduce/3-lists^foldl/2-0-"/3
    (absinthe 1.7.1) lib/absinthe/blueprint/transform.ex:122: Absinthe.Blueprint.Transform.walk/4
make: *** [build] Error 1