Moodle version update and web services not working

by Ish Kaur.  

I updated the moodle version from 2.9.2 to 3.3.3. I am geeting the following error while running the web services.

<?xml version="1.0" encoding="UTF-8"?>

-<EXCEPTION class="invalid_response_exception">

<ERRORCODE>invalidresponse</ERRORCODE>

<MESSAGE>Invalid response value detected</MESSAGE>

<DEBUGINFO>users => Invalid response value detected: username => Invalid response value detected: Invalid external api response: the value is "ADMIN_CGUINDON", the server was expecting "username" type</DEBUGINFO>

</EXCEPTION>

Any Idea?