Submit a ticketCall us

AnnouncementsAre You “Flying Blind?”

When it comes to your complex IT infrastructure, you want to ensure you have a good grasp of what’s going on to avoid any fire drills that result from guesswork. Read our white paper to learn how proactively monitoring your IT environment can help your organization while giving you peace of mind.

Get your free white paper.

Home > Success Center > Network Performance Monitor (NPM) > NPM - Knowledgebase Articles > Discovery error in NPM 11.5.2: An error while processing the results has occured. See discovery log for more details

Discovery error in NPM 11.5.2: An error while processing the results has occured. See discovery log for more details

Created by Matthew Lamb, last modified by MindTouch on Jun 23, 2016

Views: 2,556 Votes: 5 Revisions: 5


This article goes over an issue that occurs in NPM 11.5+ during a discovery where it fails with this error in the Web Console:

An error while processing the results has occured. See discovery log for more details


And this error that occurs in the Core.BusinessLayer.logs:

ERROR SolarWinds.Orion.Core.Common.CoreErrorHandler - Error occured on Business Layer call. Type: System.Data.OleDb.OleDbException
ErrorCode: '-2147467259'
Errors: 'System.Data.OleDb.OleDbErrorCollection'
Message: 'Unspecified error'
Data: 'System.Collections.ListDictionaryInternal'
InnerException: ''
TargetSite: 'Void .ctor(System.Data.OleDb.OleDbConnectionString, System.Data.OleDb.OleDbConnection)'
StackTrace: '   at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection)
   at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup)
   at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
   at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   at System.Data.OleDb.OleDbConnection.Open()
   at SolarWinds.Orion.Core.Common.DALs.DiscoveryDatabaseDAL.OleDbHelperExecuteScalar(String query)
   at SolarWinds.Orion.Core.Common.DALs.DiscoveryDatabaseDAL.GetInterfaceTypeDescription(Int32 ifType)
   at SolarWinds.Orion.Core.Discovery.DataAccess.DiscoveryDatabase.LoadInterfacesAndVolumesForNode(DiscoveryNode discNode, IEnumerable`1 plugs)
   at SolarWinds.Orion.Core.BusinessLayer.CoreBusinessLayerService.GetVolumesAndInterfacesForDiscoveryNode(DiscoveryNode discoveryNode)
   at SyncInvokeGetVolumesAndInterfacesForDiscoveryNode(Object , Object[] , Object[] )
   at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
   at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage41(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage4(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage3(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage2(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage1(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)'
HelpLink: ''
Source: 'Microsoft JET Database Engine'


NPM version 11.5+


This issue occurs when Orion is either unable to communicate with or has lost connection to the OleDB on the server it is installed on. Why this occurs are generally one of 4 possibilities:


  • Orion is not able to access the Windows\Temp directory.

The local NETWORK SERVICE requires Read\Write to this directory to allow the Orion services to access it. If for any reason that account and rights are not present, this issue can occur.


  • The Windows\Temp directory is very large or full of files and\or files starting with "jet".

The directory has a file limit of 65536 and anything over that causes problems accessing or utilizing files within until it is cleaned up or reduced in file count.


  • Orion module engine service is nearly resource capped and is not able to allocated enough memory resources to complete the job.

The Orion Module Engine Service contains the plugins for all the Orion applications and uses a fixed memory limit. If one or more of the plugins are consuming near or at the cap for allocation, other plugins will have resource conflicts with what is left.


  • The OleDB drivers are out of date, corrupt or no longer present.


Orion Core HotFix 6 has some corrections to the causes above and it is recommend that this is applied before proceeding. You can find it here: Download


You can also upgrade to NPM 11.5.3 as it contains the above hotfix.


If the hot fix or upgrade does not correct the issue, please follow the following steps:

Note: These steps increase the memory and CPU usage on the server from a small to medium amount. Be prepared to expand or add resources as needed.

  1. Go to the directory C:\Windows\Temp.
  2. For that directory, add the Network Service account and give it Read\Write access.
  3. Once that access is granted, clean that directory out either by deleting all it's contents or moving it out to another directory.
  4. Install 2007 Office System Driver: Data Connectivity Components found on Microsoft website. 
  5. Stop all services.
  6. Go to this location: \Program Files (x86)\SolarWinds\Orion.
  7. Edit the file named SolarWinds.BusinessLayerHost.exe.config.
  8. Look for the following line: 
    <add key="ForcePluginsInSeparateProcess" value="False"/>
  9. Set the value="False" to value="True".
  10. Save the file.
  11. Restart the services.


Last modified