看来您安装的magento源代码不完整，或者模块Mage_Oauth被禁用.只需查看文件app/etc/modules/Mage_Oauth.xml，它必须看起来像这样

it seems you've got an incomplete magento source for installation or somehow the module Mage_Oauth was disabled. Just look in the file app/etc/modules/Mage_Oauth.xml, it must look like this

<config>
    <modules>
        <Mage_Oauth>
            <active>true</active>
            <codePool>core</codePool>
            <depends>
                <Mage_Core/>
            </depends>
        </Mage_Oauth>
    </modules>
</config>

也许活动标记不是true