Hi All,
struggling a bit as well I found the solution:
Driver Simulation.lvlib:Handle Errors.vi
Instrument name not found. Ensure that you called initialize for the instrument name.
(Additional Information)
Instrument Name: PowerSupply

Solution:
- In the Step Settings part, you need to be sure that the VALUE is set in the same way, so if you choose "PowerSupply" you need to be sure that all the 3 steps "Initialize PowerSupply", "Controller Board Thermal Test" and "Shut Down PowerSupply" have the "Power Supply in" Parameter Name set to "PowerSupply".

Hopefully, this can help to clarify and solve the issue.
Have a great time with TestStand