I had a case in which we use VB.NET to import a text file and it didn't work properly. My code at first was:

Dim someString As String = Encoding.ASCII.GetString(someByteArray)

After researching for a while, I found out that the text file is encoded using UTF-8. Thus, switching it to the following code make it work properly:

Dim someString As String = Encoding.UTF8.GetString(someByteArray)

Encoding matters!