VaultClient.Sys.ListAuth() failing

[cfador]

This code line:
Dictionary<string, AuthMount> authList = await _authenticatedVaultClient.Sys.ListAuth();

is failing with the following error:

Newtonsoft.Json.JsonSerializationException: Error converting value "835c7e14-e347-a330-8d9d-fe67e4701518" to type 'Vault.Endpoints.Sys.AuthMount'. Path 'request_id', line 1, position 266. ---> System.ArgumentException: Could not cast or convert from System.String to Vault.Endpoints.Sys.AuthMount.
at Newtonsoft.Json.Utilities.ConvertUtils.EnsureTypeAssignable(Object value, Type initialType, Type targetType)
at Newtonsoft.Json.Utilities.ConvertUtils.ConvertOrCast(Object initialValue, CultureInfo culture, Type targetType)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.EnsureType(JsonReader reader, Object value, CultureInfo culture, JsonContract contract, Type targetType)
--- End of inner exception stack trace ---
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.EnsureType(JsonReader reader, Object value, CultureInfo culture, JsonContract contract, Type targetType)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateDictionary(IDictionary dictionary, JsonReader reader, JsonDictionaryContract contract, JsonProperty containerProperty, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
at Vault.VaultHttpClient.d__131.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()

In both cases: with/out AppRole enabled.

How I can check if the AppRole is already enabled, so I don't need to enable it?