在针对XSD验证XML时出错

我有一个简单的 XML文件,我想针对XSD进行验证.
当我使用一些随机验证器进行验证时,我总是会收到以下错误：

Invalid content was found starting with element ‘Entities’. One of ‘{Entities}’ is expected.

这是XML：

<BusinessModel xmlns="http://schemas.testxyzxyz.de/xyz/BusinessModel" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<Entities>
    <Entity Name="Customer">
        <Attribute Name="Forename" Type="String" />
        <Attribute Name="Surname" Type="String" />
        <Attribute Name="Birthday" Type="Date" />
    </Entity>
</Entities>
</BusinessModel>

和XSD一样：

<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
        targetNamespace="http://schemas.testxyzxyz.de/xyz/BusinessModel"
        xmlns="http://schemas.testxyzxyz.de/xyz/BusinessModel">

<xsd:element name="BusinessModel" type="BusinessModelType" />

<xsd:complexType name="BusinessModelType">
    <xsd:choice minOccurs="0" maxOccurs="unbounded">
        <xsd:element name="Entities" type="EntitiesType" />
    </xsd:choice>
</xsd:complexType>

<xsd:complexType name="EntitiesType">
    <xsd:sequence>
        <xsd:element name="Entity" type="EntityType" maxOccurs="unbounded" />
    </xsd:sequence>
</xsd:complexType>

<xsd:complexType name="AttributeType">
    <xsd:attribute name="Name" type="xsd:string" use="required" />
    <xsd:attribute name="Type" type="xsd:string" use="required" />
</xsd:complexType>

<xsd:complexType name="EntityType">
    <xsd:sequence>
        <xsd:element name="Attribute" type="AttributeType" maxOccurs="unbounded" minOccurs="1" />
    </xsd:sequence>
        <xsd:attribute name="Name" type="xsd:string" use="required" />
</xsd:complexType>
</xsd:schema>

从几小时开始寻找那个问题,我仍然没有发现错误.你能发现我正确的方向吗？