Symptoms
Assume that you install SQL Server 2016 Reporting Services in SharePoint mode and you add a new data source of type Microsoft SharePoint List. You save the new data source without problem. However, when you click the Test Connection button, you receive an error message that resembles the following:
The connection string is not valid. ---> Microsoft.ReportingServices.DataExtensions.SharePointList.SPDPException: The connection string is not valid.
When you use the data source in a Reporting Services report, you receive the following error message:
The connection string is not valid.
Additionally, an error message that resembles the following is logged in the Reporting Services log file:
w3wp!processing!f!date time:: e ERROR: Throwing Microsoft.ReportingServices.ReportProcessing.ProcessingAbortedException: [AbnormalTermination:ReportProcessing], Microsoft.ReportingServices.ReportProcessing.ProcessingAbortedException: An error has occurred during report processing. ---> Microsoft.ReportingServices.DataExtensions.SharePointList.SPDPException: The connection string is not valid. at Microsoft.ReportingServices.DataExtensions.SharePointList.SPListConnection.IsLocalConnection() at Microsoft.ReportingServices.Diagnostics.DataExtensionConnectionBase.HandleImpersonation(IProcessingDataSource dataSource, DataSourceInfo dataSourceInfo, String datasetName, IDbConnection connection, Action afterImpersonationAction) at Microsoft.ReportingServices.Diagnostics.DataExtensionConnectionBase.OpenDataSourceExtensionConnection(IProcessingDataSource dataSourceObj, String connectString, DataSourceInfo dataSourceInfo, String datasetName) at Microsoft.ReportingServices.OnDemandProcessing.RuntimeDataSource.<>c__DisplayClass1.<OpenConnection>b__0() at Microsoft.ReportingServices.Diagnostics.Utilities.DefaultActivitiesFactory.CreateSyncActivityAndReportResult(RSActivityType activityType, Action action) at Microsoft.ReportingServices.OnDemandProcessing.RuntimeDataSource.OpenConnection(DataSource dataSourceObj, DataSet dataSetObj, OnDemandProcessingContext pc, DataProcessingMetrics metrics) at Microsoft.ReportingServices.OnDemandProcessing.RuntimeDataSource.OpenInitialConnectionAndTransaction() at Microsoft.ReportingServices.OnDemandProcessing.RuntimeDataSource.InitializeDataSource(ExecutedQuery existingQuery) at Microsoft.ReportingServices.OnDemandProcessing.RuntimeAtomicDataSource.Process(Boolean fromOdp) at Microsoft.ReportingServices.OnDemandProcessing.RuntimeAtomicDataSource.ProcessConcurrent(Object threadSet)
Resolution
The fix for this issue is included in the following cumulative update for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology Microsoft uses to describe software updates.
