We first create a new object GTABLE_SM2__c via the asynchronous create() metadata call.   Then we attempt to add multiple fields to this object via another create() call.

Prior to the Summer '14 update for the organization's server, this was performed without issue.   Following the Summer '14 update, this create() call fails if the number of fields is greater than 6.  The SOAP fault is "UNKNOWN_EXCEPTION: Async job could not be executed".

If the create() is performed for 6 or fewer fields on this object, then it succeeds.

This behavior has been observed for both API 29 and API 30 endpoints.

We observed this across multiple Salesforce servers, and noticed that as Summer '14 was rolled out to a server, the behavior of its organizations began showing this problem.


Sample SOAP log of the create() data for 7 fields (header trimmed):

<soap:Body>
    <create xmlns="http://soap.sforce.com/2006/04/metadata">
        <metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CustomField">
            <fullName>GTABLE_SM2__c.COLA__c</fullName>
            <label>COLA</label>
            <precision>18</precision>
            <scale>0</scale>
            <type>Number</type>
        </metadata>
        <metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CustomField">
            <fullName>GTABLE_SM2__c.COLB__c</fullName>
            <label>COLB</label>
            <length>80</length>
            <type>Text</type>
        </metadata>
        <metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CustomField">
            <fullName>GTABLE_SM2__c.COLC__c</fullName>
            <defaultValue>false</defaultValue>
            <label>COLC</label>
            <type>Checkbox</type>
        </metadata>
        <metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CustomField">
            <fullName>GTABLE_SM2__c.COLD__c</fullName>
            <label>COLD</label>
            <type>Date</type>
        </metadata>
        <metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CustomField">
            <fullName>GTABLE_SM2__c.COLE__c</fullName>
            <label>COLE</label>
            <length>5</length>
            <type>Text</type>
        </metadata>
        <metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CustomField">
            <fullName>GTABLE_SM2__c.COLF__c</fullName>
            <label>COLF</label>
            <precision>18</precision>
            <scale>9</scale>
            <type>Number</type>
        </metadata>
        <metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CustomField">
            <fullName>GTABLE_SM2__c.COLG__c</fullName>
            <defaultValue>false</defaultValue>
            <label>COLG</label>
            <type>Checkbox</type>
        </metadata>
    </create>
</soap:Body>



The full response message:

<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:sf="http://soap.sforce.com/2006/04/metadata">
    <soapenv:Body>
        <soapenv:Fault>
            <faultcode>sf:UNKNOWN_EXCEPTION</faultcode>
            <faultstring>UNKNOWN_EXCEPTION: Async job could not be executed</faultstring>
        </soapenv:Fault>
    </soapenv:Body>
</soapenv:Envelope>