XML-RPC - Fault Format

XML-RPC faults are a type of responses. If there was a problem in processing a XML-RPC request, the methodResponse element will contain a fault element instead of a params element. The fault element, like the params element, has only a single value that indicates something went wrong. A fault response might look like:

<?xml version="1.0"?>
<methodResponse>
   <fault>
      <value><string>No such method!</string></value>
   </fault>
</methodResponse>

A fault will also have an error code. XML-RPC doesn't standardize error codes at all. You'll need to check the documentation for particular packages to see how they handle faults.

A fault response could also look like:

<?xml version="1.0"?>
<methodResponse>
   <fault>
      <value>
         <struct>
            <member>
               <name>code</name>
               <value><int>26</int></value>
            </member>
    
            <member>
               <name>message</name>
               <value><string>No such method!</string></value>
            </member>
    
         </struct>
      </value>
   </fault>
</methodResponse>