When attempting to connect a worker node to the current Master node of a SQL Server Integration Services (SSIS) Scaleout, for on-prem SQL Servers, if you receive the error:
Cannot open certificate store on the machine
First off, launch SSMS on the SQL Server instance you intend to be the master. The steps to troubleshoot start with the two steps here:
3. Finally, if you are trying to add a named instance, there is one more gotcha. The Scaleout Worker is the server name not the SQL Instance name. Do not provide the full named instance name, for example, "SQLSERVER-1INSTANCENAME", only provide the server name, in this case, "SQLSERVER-1".