完全错误：

Error CREATEing SolrCore 'product_v2': Unable to create core [product_v2] Caused by: _version_ field must exist in schema and be searchable (indexed or docValues) and retrievable(stored or docValues) and not multiValued (_version_ is multiValued

架构.xml

<?xml version="1.0" encoding="UTF-8" ?>
<schema name="product_v2" version="1.5">

    <field name="_version_" type="long" indexed="true" stored="true" multiValued="false"/>

    <!-- points to the root document of a block of nested documents. Required for nested
       document support, may be removed otherwise
    -->
    <field name="_root_" type="string" indexed="true" stored="false"/>

    <!-- Only remove the "id" field if you have a very good reason to. While not strictly
      required, it is highly recommended. A <uniqueKey> is present in almost all Solr
      installations. See the <uniqueKey> declaration below where <uniqueKey> is set to "id".
    -->
    <field name="id" type="string" indexed="true" stored="true" required="true" multiValued="false" />
    <field name="sku" type="string" indexed="true" stored="true" required="true" multiValued="false" />
    <field name="title" type="string" indexed="true" stored="true" required="true" multiValued="false" />
    <field name="type" type="string" indexed="true" stored="true" required="true" multiValued="false" />

    <!-- Field to use to determine and enforce document uniqueness.
         Unless this field is marked with required="false", it will be a required field
      -->
    <uniqueKey>id</uniqueKey>

    <fieldType name="string" class="solr.StrField" sortMissingLast="true" />
    <fieldType name="boolean" class="solr.BoolField" sortMissingLast="true"/>
    <fieldType name="int" class="solr.TrieIntField" precisionStep="0" positionIncrementGap="0"/>
    <fieldType name="float" class="solr.TrieFloatField" precisionStep="0" positionIncrementGap="0"/>
    <fieldType name="long" class="solr.TrieLongField" precisionStep="0" positionIncrementGap="0"/>
    <fieldType name="double" class="solr.TrieDoubleField" precisionStep="0" positionIncrementGap="0"/>
</schema>

不幸的是，我不知道该怎么办。据我所知，该版本符合所有要求。我在过去使用过大量Solr，没有问题，但这是我第一次使用Solrcloud+Zookeeper。
Solr版本为6.3.0