When we try to create a job (see attached XML), we get "[InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @ com.google.ads.api.services.common.error.InternalApiError.<init>(InternalApiErro]". If we change the operation to ADD instead of SET, it seems to work fine.
<?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>
<ns1:RequestHeader xmlns:ns1="
https://adwords.google.com/api/adwords/cm/v201509" soapenv:mustUnderstand="0">
<ns1:clientCustomerId>XXXXXXXXXX</ns1:clientCustomerId>
<ns1:developerToken>YYYYYYYYYYYYYYYY</ns1:developerToken>
<ns1:userAgent>ZZZZZ (AwApi-Java, AdWords-Axis/2.7.0, Common-Java/2.7.0, Axis/1.4, Java/1.8.0_60, maven)</ns1:userAgent>
<ns1:validateOnly>false</ns1:validateOnly>
<ns1:partialFailure>false</ns1:partialFailure>
</ns1:RequestHeader>
</soapenv:Header>
<soapenv:Body>
<mutate xmlns="
https://adwords.google.com/api/adwords/cm/v201509">
<operations>
<operator>SET</operator>
<operand/>
</operations>
</mutate>
</soapenv:Body>
</soapenv:Envelope>
<?xml version="1.0" encoding="UTF-8"?><soap:Envelope xmlns:soap="
http://schemas.xmlsoap.org/soap/envelope/">
<soap:Header>
<ResponseHeader xmlns="
https://adwords.google.com/api/adwords/cm/v201509">
<requestId>000524a41b9826d00a81339089049d5a</requestId>
<serviceName>BatchJobService</serviceName>
<methodName>mutate</methodName>
<operations>1</operations>
<responseTime>280</responseTime>
</ResponseHeader>
</soap:Header>
<soap:Body>
<soap:Fault>
<faultcode>soap:Server</faultcode>
<faultstring>[InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @ com.google.ads.api.services.common.error.InternalApiError.<init>(InternalApiErro]</faultstring>
<detail>
<ApiExceptionFault xmlns="
https://adwords.google.com/api/adwords/cm/v201509">
<message>[InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @ com.google.ads.api.services.common.error.InternalApiError.<init>(InternalApiErro]</message>
<ApplicationException.Type>ApiException</ApplicationException.Type>
<errors xmlns:xsi="
http://www.w3.org/2001/XMLSchema-instance" xsi:type="InternalApiError">
<fieldPath/>
<trigger/>
<errorString>InternalApiError.UNEXPECTED_INTERNAL_API_ERROR</errorString>
<ApiError.Type>InternalApiError</ApiError.Type>
<reason>UNEXPECTED_INTERNAL_API_ERROR</reason>
</errors>
</ApiExceptionFault>
</detail>
</soap:Fault>
</soap:Body>
</soap:Envelope>