Submit a ticketCall us

AnnouncementsFace your biggest database issues head-on

Our new eCourse helps you navigate SQL Server performance blocks by teaching you how to recognize and deal with the three DBA Disruptors: Performance Hog, Blame Shifter, and Query Blocker. Register today to learn how to defend your environment and fend off menacing disruptions.

Register for your free eCourse.

Home > Success Center > Network Performance Monitor (NPM) > NPM - Knowledgebase Articles > Core Business Layer plugin does not start

Core Business Layer plugin does not start

Updated June 23, 2017


The Core Business Layer plugin does not start and the following error is found in the Core.BusinessLayer.log file:

2017-03-28 09:51:08,918 [7] FATAL SolarWinds.Orion.Core.BusinessLayer.CoreBusinessLayerPlugin - (null)  Unhandled Exception caught in plugin startup.
System.ArgumentException: An item with the same key has already been added.
   at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at SolarWinds.Orion.Core.BusinessLayer.BackgroundInventory.InventoryManager..ctor(Int32 engineID)
   at SolarWinds.Orion.Core.BusinessLayer.CoreBusinessLayerPlugin.ScheduleBackgroundInventory()
   at SolarWinds.Orion.Core.BusinessLayer.CoreBusinessLayerPlugin.Start()


All Orion Platform versions


This issue occurs when there is a duplicate or an older DLL present in the installation folder.


Remove the duplicate DLLS.

Note: It is also possible that there are duplicate DLLs in a duplicate installation folder and in the backup and hotfix folders.


Last modified