Why “Data at the root level is invalid. Line 1, position 1.” for XML Document?

Question

I am using a third-party DLL which transmits an XML document over the internet.

Why would the DLL be throwing the following exception?

Data at

Answer 1

I can give you two advices:

1. It seems you are using "LoadXml" instead of "Load" method. In some cases, it helps me.
2. You have an encoding problem. Could you check the encoding of the XML file and write it?