Q:

Creating Data Extension with SOAP API: 400 Error

I new to webservices and practices interacting with SFMC with SOAP calls. I am attempting to create a data extension, but keep getting a 400 error. I am using SOAP UI to make the calls.  
Here is my XML envelope:
<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <soapenv:Header>
         <fueloauth xmlns="http://exacttarget.com">ACCESS TOKEN</fueloauth>
   </soapenv:Header>
<soapenv:Body>
      <CreateRequest xmlns="http://exacttarget.com/wsdl/partnerAPI">
         <Options/>
         <Objects xsi:type="DataExtension">
            <PartnerKey xsi:nil="true"/>
            <ObjectID xsi:nil="true"/>
            <Name>Sam_DE</Name>
            <IsSendable>false</IsSendable>
            <Fields>
               <Field>
                  <Name>EmailAddress</Name>
                  <FieldType>EmailAddress</FieldType>
                  <IsPrimaryKey>true</IsPrimaryKey>
                  <IsRequired>true</IsRequired>
               </Field>
               <Field>
                  <Name>SubscriberKey</Name>
                  <FieldType>Text</FieldType>
                  <IsRequired>false</IsRequired>
               </Field>
               <Field>
                  <Name>Date</Name>
                  <FieldType>Date</FieldType>
                  <DefaultValue>getdate()</DefaultValue>
                  <IsRequired>true</IsRequired>
               </Field>
               <Field>
                  <Name>Average_Order_Value</Name>
                  <FieldType>Decimal</FieldType>
                  <IsRequired>true</IsRequired>
                  <Precision>10</Precision>
                  <Scale>2</Scale>
               </Field>
               <Field>
                  <Name>Is_Proofing_Customer?</Name>
                  <FieldType>Boolean</FieldType>
                  <DefaultValue>true</DefaultValue>
                  <IsRequired>true</IsRequired>
               </Field>
               <Field>
                  <Name>Number_of_Clusters</Name>
                  <FieldType>Number</FieldType>
                  <IsRequired>false</IsRequired>
               </Field>
               <Field>
                  <Name>Telephone</Name>
                  <FieldType>Phone</FieldType>
                  <IsRequired>false</IsRequired>
               </Field>
               <Field>
                  <Name>Locale</Name>
                  <FieldType>Locale</FieldType>
                  <IsRequired>false</IsRequired>
               </Field>
            </Fields>
            <CustomerKey>SamDE01</CustomerKey>
         </Objects>
      </CreateRequest>
   </soapenv:Body>

I will appreciate help with debugging this.

A:

You can't include a ? character in a DE field name.
If you change <Name>Is_Proofing_Customer?</Name> to <Name>Is_Proofing_Customer</Name> then your request will work successfully.
I have modified your request payload and the following request works for me in SoapUI. Note, replace webservice.s7.exacttarget.com/Service.asmx with the endpoint to your Marketing Cloud Instance and add your accessToken retrieved from the Authentication Service.
<?xml version="1.0" encoding="UTF-8"?>
 <s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope" xmlns:a="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
  <s:Header>
     <a:Action s:mustUnderstand="1">Create</a:Action>
     <a:MessageID>urn:uuid:7e0cca04-57bd-4481-864c-6ea8039d2ea0</a:MessageID>
     <a:ReplyTo>
        <a:Address>http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous</a:Address>
     </a:ReplyTo>
     <a:To s:mustUnderstand="1">https://webservice.s7.exacttarget.com/Service.asmx</a:To>
     <fueloauth xmlns="http://exacttarget.com">accesstoken</fueloauth>
  </s:Header>
 <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
     <CreateRequest xmlns="http://exacttarget.com/wsdl/partnerAPI">
        <Options/>
        <Objects xsi:type="DataExtension">
           <PartnerKey xsi:nil="true"/>
           <ObjectID xsi:nil="true"/>
           <Name>Sam_DE</Name>
           <IsSendable>false</IsSendable>
           <Fields>
              <Field>
                 <Name>EmailAddress</Name>
                 <FieldType>EmailAddress</FieldType>
                 <IsPrimaryKey>true</IsPrimaryKey>
                 <IsRequired>true</IsRequired>
              </Field>
              <Field>
                 <Name>SubscriberKey</Name>
                 <FieldType>Text</FieldType>
                 <IsRequired>false</IsRequired>
              </Field>
              <Field>
                 <Name>Date</Name>
                 <FieldType>Date</FieldType>
                 <DefaultValue>getdate()</DefaultValue>
                 <IsRequired>true</IsRequired>
              </Field>
              <Field>
                 <Name>Average_Order_Value</Name>
                 <FieldType>Decimal</FieldType>
                 <IsRequired>true</IsRequired>
                 <Precision>10</Precision>
                 <Scale>2</Scale>
              </Field>
              <Field>
                 <Name>Is_Proofing_Customer</Name>
                 <FieldType>Boolean</FieldType>
                 <DefaultValue>true</DefaultValue>
                 <IsRequired>true</IsRequired>
              </Field>
              <Field>
                 <Name>Number_of_Clusters</Name>
                 <FieldType>Number</FieldType>
                 <IsRequired>false</IsRequired>
              </Field>
              <Field>
                 <Name>Telephone</Name>
                 <FieldType>Phone</FieldType>
                 <IsRequired>false</IsRequired>
              </Field>
              <Field>
                 <Name>Locale</Name>
                 <FieldType>Locale</FieldType>
                 <IsRequired>false</IsRequired>
              </Field>
           </Fields>
           <CustomerKey>SamDE01</CustomerKey>
        </Objects>
     </CreateRequest>
 </s:Body>
</s:Envelope>

