This error can occur when you are changing an execution server from one environment to another on Silk Central.
Please see the below steps to delete execution server associations on the original machine without using Silk Central. This is useful if Silk Central has been uninstalled on the original machine.
On the original machine:
1. Delete the AgentBase folder at C:\ProgramData\SilkCentral.
2. Go to SQL Management Studio. Please see the below three delete queries that need to be run.
You will need to check the referenced tables first for the execution server names and values. Check the tables for the info and modify the delete queries to match it.
DELETE FROM [demodb].[dbo].[SCC_Orders_ExecServers] WHERE ExecServerID_pk_fk = 18
DELETE FROM [demodb].[dbo].[SCC_ExecServers] WHERE Name = 'localhost'
DELETE FROM [demodb].[dbo].[SCC_Locations] WHERE Name = 'Local'
3. Restart the execution server.
On the new machine:
1. Log out of Silk Central and log back in again.
2. You should now be able to add the original machine as an execution server in your Execution Environment in Silk Central.