I was trying to follow the instructions at https://developer.intuit.com/app/developer/qbdesktop/docs/get-started/first-steps-with-the-sdktestpl... and when I run "C:\Program Files\Intuit\IDN\QBSDK15.0\tools\SDKTest\SDKTestPlus3.exe" and click on the "Open Connection" button I get an error:

I'm running QuickBooks Premiere 2021 and the SDK has been installed.

Any ideas?