XML error while connecting Flex 4 to Java using BlazeDS 4 in Flash Builder

You might face of the following error while creating data service using BlazeDS.

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ERROR: XML parse error: Error on line 1 of document: cvc-elt.1: Can not find the declaration of element ‘model’. Nested exception: Can not find the declaration of element ‘model’.
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In that case make sure you download latest BlazeDS 4 nightly build. Once you unzip the file you will get war file. Just dump that with different name under Tomcat/weapps directory. You have to copy files from lib directory into existing application webapps//WEB-INF/lib directory.