No idea, but you're not using the latest plugin. Download it here:
https://github.com/AndrewAMD/SierraChartZorroPlugin/releases/tag/v1.0.0.3

The documentation has completely changed, too. Read:
https://github.com/AndrewAMD/SierraChartZorroPlugin

Also, I have no plans on supporting that method of access. Use AssetHistory:
https://manual.zorro-project.com/loadhistory.htm

I might eventually put in a separate brokerCommand if I have time to spare.
(Or I can expedite it with a sponsorship.)