This post is being made as I could not find any resources on here for this error, and this is how I resolved the problem.
I was getting “Service could not fulfill request” errors on the home screen of the Mobile Application immediately after upgrading to 26R1.
Turning on Request Profiled keyed me into the exception that was being thrown on the server side (shown below).
The fix:
My Global Assembly Cache had an older version of Newtonsoft.Json.dll. I removed that assembly from the GAC, did an IISREST and the error went away.
Method not found: 'Void Newtonsoft.Json.Linq.JToken.WriteTo(Newtonsoft.Json.JsonWriter)'.
Stack Trace:
at PX.Data.PXFirstChanceExceptionLogger.ProfilerFirstChanceException(Object o, FirstChanceExceptionEventArgs args)at PX.Api.Mobile.Services.Routing.UriMetaConverter.WriteJson(JsonWriter writer, UriMeta value, JsonSerializer serializer)at Newtonsoft.Json.JsonConverter1.WriteJson(JsonWriter writer, Object value, JsonSerializer serializer)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeConvertable(JsonWriter writer, JsonConverter converter, Object value, JsonContract contract, JsonContainerContract collectionContract, JsonProperty containerProperty)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeDictionary(JsonWriter writer, IDictionary values, JsonDictionaryContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
at PX.Api.Mobile.ScreenMetaConverter.WriteJsonInternal(JsonWriter writer, Object value, JsonSerializer serializer, Type type, String name, JsonPropertyAttribute propertyAttribute, Boolean isIgnore, Boolean isExtract, Object defaultValue)
at PX.Api.Mobile.ScreenMetaConverter.IterateThroughtObject(JsonWriter writer, Object value, JsonSerializer serializer)
at PX.Api.Mobile.ScreenMetaConverter.WriteJsonInternal(JsonWriter writer, Object value, JsonSerializer serializer, Type type, String name, JsonPropertyAttribute propertyAttribute, Boolean isIgnore, Boolean isExtract, Object defaultValue)
at PX.Api.Mobile.ScreenMetaConverter.WriteJson(JsonWriter writer, Object value, JsonSerializer serializer)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeConvertable(JsonWriter writer, JsonConverter converter, Object value, JsonContract contract, JsonContainerContract collectionContract, JsonProperty containerProperty)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)
at Microsoft.AspNetCore.Mvc.Formatters.JsonOutputFormatter.WriteObject(TextWriter writer, Object value)
at Microsoft.AspNetCore.Mvc.Formatters.JsonOutputFormatter.
