Unexpected character encountered while parsing value

[irgnosis]

Installed product versions

• Visual Studio: 2015 Enterprise
• This extension: 1.4.45

Description

Getting error "Unexpected character encountered while parsing value" when I click on Update Image Sprite in visual studio on an existing sprite

Steps to recreate

Right click on an existing sprite and click on "Update Image Sprite" in visual studio 2015. You will see below error:

11/22/2016 6:37:40 PM: Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: <. Path '', line 0, position 0.
at Newtonsoft.Json.JsonTextReader.ParseValue()
at Newtonsoft.Json.JsonTextReader.ReadInternal()
at Newtonsoft.Json.JsonTextReader.Read()
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.ReadForType(JsonReader reader, JsonContract contract, Boolean hasConverter)
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 ImageSprites.SpriteDocument.FromJSON(String json, String fileName)
at ImageSprites.SpriteDocument.d__43.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ImageSpritesVsix.SpriteService.d__7.MoveNext() in C:\projects\imagesprites\src\ImageSpritesVsix\SpriteService.cs:line 89
11/22/2016 6:42:21 PM: Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: <. Path '', line 0, position 0.
at Newtonsoft.Json.JsonTextReader.ParseValue()
at Newtonsoft.Json.JsonTextReader.ReadInternal()
at Newtonsoft.Json.JsonTextReader.Read()
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.ReadForType(JsonReader reader, JsonContract contract, Boolean hasConverter)
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 ImageSprites.SpriteDocument.FromJSON(String json, String fileName)
at ImageSprites.SpriteDocument.d__43.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ImageSpritesVsix.SpriteService.d__7.MoveNext() in C:\projects\imagesprites\src\ImageSpritesVsix\SpriteService.cs:line 89

Current behavior

Error is thrown

Expected behavior

Sprite png and css should be updated