Web service XML error

[cricrides]

Hello

I want to use a web service I have created.
When I call the webservice via VB Net, I get an message telling me that I have an error in my XML line 1 pos 327.
The XML answer is

<?xml version="1.0" encoding="utf-8"?>
<string xmlns="http://xxxx/">3.0.0.4</string>

My code:

Dim AService As New A_WebService.A_WebService()
version = AService.GetFileVersion(FileName)

I don't know where to search anymore to find the root of this problem.
Anyone able to help me?

regards

cricri