Removed interface still showing in SolarWinds

Initially you can try to delete the interface and then run the DB maintenance and check the website (after doing a hard refresh).

It appears that this node you have is still in the Nodes table in the database. Although this is not expected behavior, it does occasionally happen. You can manually delete it from the nodes table in the DB. It will require briefly stopping the Orion services.
 
First, right-click on the node in question in the Orion System Manager and select "Node Details." There will be a Node ID number - make a note of this.
 
 
Go to Start -> Programs -> SolarWinds Orion -> Advanced Features -> Shutdown NetPerfMon.
 
When the list of services appears, go to File -> Shutdown Everything.
 
Next, go to Start -> Programs -> SolarWinds Orion -> Database Utilities -> Database Manager.
 
If your SQL server is not present, add it by clicking the Add Server button in the upper left.
 
Once your server is there, expand it to view the list of databases. The Orion database is called NetPerfMon by default.
 
Expand the database and find the table called "Nodes".
 
Right-click the Nodes table, and choose "Query Table." This will pop up a blank window with "Select Top 1000* from Nodes" written in it. Click "Refresh."
 
Change the radial button to "Read/Write"
 
Erase the "Select" statement from the Query Window, so it is now blank.
 
Type in the following: Delete From Nodes where NodeID = (insert NodeID you want to delete here) and click refresh.
 
Right-click the Nodes table and choose "Query" and then "Refresh" again - your Node should be gone.

I needed to keep the Node itself.  So I followed your instructions, but removed the interface from the Interface table instead.  It worked.  Thank you Mark.

I have to routinely delete rows from the Interfaces table due to this issue.  This is the only solution that SolarWinds support ever provides. 

I will on occasion have to use System Manager to delete an interface that, for example, gets changed from a plain NIC to a Team NIC - I List Resources, check the new NIC, and go back and right-click the old NIC and say "Delete Interface."  Is that the same thing?

Paul
 

Paul - that is not the same thing.  What occasionally happens is after you do the steps that you have listed, the interface that you have removed from System Manager is still being displayed on the web interface of SolarWinds.  It will not be listed on the node in System Manager as a selected interface.  Now I have only seen this happen to me twice on this particular poller that we have, which we are monitoring over 1450 nodes with 4380 interfaces.