JsonFileHelper.TryGet() Return System.Text.Json.JsonReaderException

[hamid65217]

When I Called TryGet() Method in Program.cs , This Exception is thrown:
System.Text.Json.JsonReaderException: ''0xEF' is an invalid start of a value. LineNumber: 0 | BytePositionInLine: 0.'
on this line of method:
using(var jsonDocument = JsonDocument.Parse(jsonContent));