Im not able to edit content type fields, error An item with the same key has already been added

Question

Im having this error when try to edit fields for a content type. Same problem when try to list items for a content field.

"An item with the same key has already been added."

Stacktrace

" at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)\r\n at System.Collections.Generic.Dictionary2.Insert(TKey key, TValue value, Boolean add)\r\n at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable1 source, Func2 keySelector, Func2 elementSelector, IEqualityComparer1 comparer)\r\n at ToSic.Eav.WebApi.ContentTypeApi.<>c__DisplayClass17_0.<GetFields>b__1(IContentTypeAttribute a)\r\n at System.Linq.Enumerable.WhereSelectEnumerableIterator2.MoveNext()\r\n at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IEnumerable values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)\r\n at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)\r\n at System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, Encoding effectiveEncoding)\r\n at System.Net.Http.Formatting.JsonMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, Encoding effectiveEncoding)\r\n at System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, HttpContent content)\r\n at System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStreamAsync(Type type, Object value, Stream writeStream, HttpContent content, TransportContext transportContext, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Tracing.ITraceWriterExtensions.d__24.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.WebHost.HttpControllerHandler.d__1b.MoveNext()"

Im still able to add or edit new items with buttons from template, and can add items from Data Tab.

I don´t know when the problem started because is possible to add or edit items, but today i tried to add a validation in some field and error appeared.

Any Idea what can be happening ?

Answer 1

I was looking a little bit into insights and I found that my Content Type had an attribute with duplicated key, I deleted the duplicated entry and started to work again, now im able to edit fields.

The problem for list all items was related with some Unicode characters into my string fields (emoticons), it appears unicode characters are not allowed in admin mode. Fields are being displayed normally in View Mode.