checker bug

[Trolldemorted]

Flag failed: '3' is an invalid escapable character within a JSON string. The string should be correctly escaped. Path: $.notes | LineNumber: 0 | BytePositionInLine: 185. (System.Text.Json.JsonException)
   at System.Text.Json.ThrowHelper.ReThrowWithPath(ReadStack& readStack, JsonReaderException ex)
   at System.Text.Json.JsonSerializer.ReadCore(JsonSerializerOptions options, Utf8JsonReader& reader, ReadStack& readStack)
   at System.Text.Json.JsonSerializer.ReadCore(Type returnType, JsonSerializerOptions options, Utf8JsonReader& reader)
   at System.Text.Json.JsonSerializer.Deserialize(String json, Type returnType, JsonSerializerOptions options)
   at System.Text.Json.JsonSerializer.Deserialize[TValue](String json, JsonSerializerOptions options)
   at GamemasterChecker.GamemasterClient.FetchSessionAsync(Int64 sessionId, CancellationToken token) in /src/GamemasterClient.cs:line 297
   at GamemasterChecker.GamemasterChecker.GetFlagFromSession(CheckerTaskMessage task, CancellationToken token) in /src/GamemasterChecker.cs:line 276
   at GamemasterChecker.GamemasterChecker.HandleGetFlag(CheckerTaskMessage task, CancellationToken token) in /src/GamemasterChecker.cs:line 67
   at GamemasterChecker.Controllers.CheckerController.Flag(String content) in /src/Controllers/CheckerController.cs:line 114
InnerException:
Flag failed: '3' is an invalid escapable character within a JSON string. The string should be correctly escaped. LineNumber: 0 | BytePositionInLine: 185. (System.Text.Json.JsonReaderException)
   at System.Text.Json.ThrowHelper.ThrowJsonReaderException(Utf8JsonReader& json, ExceptionResource resource, Byte nextByte, ReadOnlySpan`1 bytes)
   at System.Text.Json.Utf8JsonReader.ConsumeStringAndValidate(ReadOnlySpan`1 data, Int32 idx)
   at System.Text.Json.Utf8JsonReader.ConsumeString()
   at System.Text.Json.Utf8JsonReader.ConsumeValue(Byte marker)
   at System.Text.Json.Utf8JsonReader.ReadSingleSegment()
   at System.Text.Json.Utf8JsonReader.Read()
   at System.Text.Json.JsonSerializer.ReadCore(JsonSerializerOptions options, Utf8JsonReader& reader, ReadStack& readStack)

grrr