xml LoadData - Data at the root level is invalid Line 1 position 1

Question

I m trying to parse some XML inside a WiX installer   The XML would be an object of all my errors returned from a web server   I m getting the error in the question title with this code   XmlDocument xml   new XmlDocument    try       xml LoadXml myString     catch  Exception ex        System IO File WriteAllText   C  text txt   myString     r n r n    ex Message       throw ex      myString is this  as seen in the output of text txt    lt  xml version  1 0  encoding  utf-8   gt   lt Errors gt  lt  Errors gt    text txt comes out looking like this    lt  xml version  1 0  encoding  utf-8   gt   lt Errors gt  lt  Errors gt   Data at the root level is invalid  Line 1  position 1    I need this XML to parse so I can see if I had any errors   Edit  This question is not a duplicate as marked   In that question the person asking the question was using LoadXml to parse an XML file  I m parsing a string  which is the correct use of LoadXml

User · Answer

The issue here was that myString had that header line   Either there was some hidden character at the beginning of the first line or the line itself was causing the error   I sliced off the first line like so   xml LoadXml myString Substring myString IndexOf Environment NewLine       This solved my problem

User · Answer

Use Load   method instead  it will solve the problem  See more

User · Answer

I have found out one of the solutions  For your code this could be as follows -  XmlDocument xml   new XmlDocument    try          assuming the location of the file is in the current directory         assuming the file name be loadData xml     string myString      loadData xml       xml Load myString     catch  Exception ex        System IO File WriteAllText   C  text txt   myString     r n r n    ex Message       throw ex

User · Answer

At first I had problems escaping the  quot  amp  quot  character  then diacritics and special letters were shown as question marks and ended up with the issue OP mentioned  I looked at the answers and I used  Ringo s suggestion to try Load   method as an alternative  That made me realize that I can deal with my response in other ways not just as a string  using System IO Stream instead of string solved all the issues for me  var response   await this httpClient GetAsync url   var responseStream   await response Content ReadAsStreamAsync    var xmlDocument   new XmlDocument    xmlDocument Load responseStream    The cool thing about Load   is that this method automatically detects the string format of the input XML  for example  UTF-8  ANSI  and so on   See more

User · Answer

If your xml is in a string use the following to remove any byte order mark           xml   new Regex     lt    xml      gt    Replace xml

User · Answer

Save your file with different encoding   File   Save file as      Save as UTF-8 without signature   In VS 2017 you find encoding as a dropdown next to Save button

User · Answer

I Think that the problem is about encoding  That s why removing first line with encoding byte  might solve the problem   My solution for Data at the root level is invalid  Line 1  position 1  in XDocument Parse xmlString  was replacing it with XDocument Load  new MemoryStream  xmlContentInBytes       I ve noticed that my xml string looked ok    lt  xml version  1 0  encoding  utf-8   gt    but in different text editor encoding it looked like this     lt  xml version  1 0  encoding  utf-8   gt    At the end i did not need the xml string but xml byte    If you need to use the string you should look for  invisible  bytes in your string and play with encodings to adjust the xml content for parsing or loading   Hope it will help

User · Answer

Main culprit for this error is logic which determines encoding when converting Stream or byte   array to  NET string  Using StreamReader created with 2nd constructor parameter detectEncodingFromByteOrderMarks set to true  will determine proper encoding and create string which does not break XmlDocument LoadXml method  public string GetXmlString string url        using var stream   GetResponseStream url       using var reader   new StreamReader stream  true       return reader ReadToEnd       no exception on  LoadXml     Common mistake would be to just blindly use UTF8 encoding on the stream or byte    Code bellow would produce string that looks valid when inspected in Visual Studio debugger  or copy-pasted somewhere  but it will produce the exception when used with Load or LoadXml if file is encoded differently then UTF8 without BOM  public string GetXmlString string url        byte   bytes   GetResponseByteArray url       return System Text Encoding UTF8 GetString bytes      potentially exception on  LoadXml

User · Answer

The hidden character is probably BOM  The explanation to the problem and the solution can be found here  credits to James Schubert  based on an answer by James Brankin found here    Though the previous answer does remove the hidden character  it also removes the whole first line  The more precise version would be   string  byteOrderMarkUtf8   Encoding UTF8 GetString Encoding UTF8 GetPreamble     if  xml StartsWith  byteOrderMarkUtf8         xml   xml Remove 0   byteOrderMarkUtf8 Length       I encountered this problem when fetching an XSLT file from Azure blob and loading it into an XslCompiledTransform object  On my machine the file looked just fine  but after uploading it as a blob and fetching it back  the BOM character was added

User · Answer

I ve solved this issue by directly editing the byte array  Collect the UTF8 preamble and remove directly the header  Afterward you can transform the byte  to a string with GetString method  see below  The  r and  t I ve removed as well  just as precaution   XmlDocument configurationXML   new XmlDocument    List lt byte gt  byteArray   new List lt byte gt  webRequest downloadHandler data    foreach byte singleByte in Encoding UTF8 GetPreamble           byteArray RemoveAt byteArray IndexOf singleByte      string xml   System Text Encoding UTF8 GetString byteArray ToArray            xml   xml Replace    r               xml   xml Replace    t

User · Answer

if we are using XDocument Parse       Use   it resolves the issue

[c#] xml.LoadData - Data at the root level is invalid. Line 1, position 1

Examples related to c#

Examples related to xml

Examples related to xml-parsing

Examples related to wix