我目前正在升级到 8.1，但是在运行 contenttestingupdate.aspx 管理页面时，它失败并出现以下错误：
Exception: System.Reflection.TargetInvocationException:
Exception has been thrown by the target of an invocation.
---> System.ArgumentNullException: Value cannot be null. Parameter name: fieldNameTranslator
at Sitecore.ContentSearch.Linq.Solr.SolrIndexParameters..ctor(IIndexValueFormatter valueFormatter, IFieldQueryTranslatorMap`1 fieldQueryTranslators, FieldNameTranslator fieldNameTranslator, IExecutionContext[] executionContexts, IFieldMapReaders fieldMap, Boolean convertQueryDatesToUtc)
at Sitecore.ContentSearch.SolrProvider.LinqToSolrIndex`1..ctor(SolrSearchContext context, IExecutionContext[] executionContexts)
at Sitecore.ContentSearch.SolrProvider.SolrSearchContext.GetQueryable[TItem](IExecutionContext[] executionContexts)
at Sitecore.ContentTesting.ContentSearch.TestingSearch.GetAllTests()
at Sitecore.ContentTesting.Upgrade.PostUpgradeRunner.GetTests()
at Sitecore.ContentTesting.Upgrade.PostUpgradeRunner.Run(StepOptions steps)
at Sitecore.ContentTesting.Upgrade.ContentTestingUpgrade.StartUpgrade(StepOptions options) --- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)
at Sitecore.Jobs.JobRunner.RunMethod(JobArgs args)
at (Object , Object[] )
at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
at Sitecore.Jobs.Job.ThreadEntry(Object state)
所有 lucene 配置都被禁用，因为它使用 SOLR。
可能是什么问题呢？此外，是否可以跳过此步骤以继续升级？