Object reference not set to an instance of an object.

This is a design "feature" from Solarwinds, and if you search the forum for it, you will find MANY people have discovered it.

Many people have also discovered its non-intuitive and cryptic frustration.  For proof, follow this link that searches the forum for that topic:

https://thwack.solarwinds.com/search.jspa?q=Object%20reference%20not%20set%20to%20an%20instance%20of%20an%20object

Let me clue you into the cause and the correction:

1. You're trying to remove something that is still monitored by something like a Custom Poller (UnDP).

2. Solarwinds won't allow it to be removed until that monitoring is deleted.

Fix:

The best solution, in my experience, is locating the UnDP referencing the node and removing from monitoring the node you wish to remove.

1. Use the UnDP tool to remove any pollers assigned to the node before deleting the node.
2. Use the "All nodes" tree in the UnDP tool on the top left.Expand this down to the node level, then expand the node to view all pollers assigned to it.
3. Right-click and unassign the poller from here.

But there are other fixes found by other folks, and one of them may work if the first one I mentioned does not:

• Upgrade to the current version of Solarwinds software and apply the current hot fixes for it.
• Running the Solarwinds Configuration Wizard (for website only) may resolve it. (object reference not set to an instance of an object )
• Recreate the web site in IIS (NPM add or edit view error "Object reference not set to an instance of an object" )
• Open a Support Case online with Solarwinds, then create and upload the Diagnostics and attach them to the case, then call Solarwinds with the Case Number (Transaction Showing Down with "Object reference not set to an instance of an object" error )

Researching the problem via the first link I posted will give you good options to try, but the first fix I provided has been the best one, in my experience.

Swift Packets!  Let us know what fixes it for you!

Rick Schroeder

Thank you for links and description. Unfortunately there are no custom pollers assigned to that node so I am trying other options.

Thanks for the response.

Although you may find the other options could help, after a certain amount of time I stop the research and focus on creating a Support Ticket online, I create and upload the Diagnostics and attach them to the ticket, and I call Support with the ticket ID and ask for help.

Let us know what your particular fix for this was, please!

Swift packets!

Rick Schroeder

Case: OBJECT REFERENCE NOT SET TO AN INSTANCE OF AN OBJECT - just for one Node.

Solution: Assign Poller Engine

It turned out after Orion platform upgrade that I was able to get into Edit settings of that unknown node that Polling Engine is not assigned. So I tried to put it on also changed IP and Name of that node and after error while saving I was able to delete it from Managed Nodes view as it appear there.

In my case I believe that assigning nodes to polling engine in Database Manager would solve it.

--Check for Polling Engine ID

SELECT * FROM [dbo].[Engines]

--Set nodes to use polling engine from previous query

Update Nodes

Set EngineID=''