Matt, thanks for reaching out. I’ll check it and come back to you!

Brooklyn 10.0.19 installed just fine.

Matt, what edition is this org? Is it Professional Edition by chance? It is a known issue that Millau is not currently compatible with Professional Edition on account of Millau’s support for Platform Events, which is only supported on Developer, Enterprise, Unlimited, and Performance Editions (https://help.salesforce.com/articleView?id=platform_events.htm&type=5)

Zach,

Good catch. Apparently my trial version is the Professional Edition, somehow? I don’t recall having a choice when I signed up for the trial. I have a case with salesforce to get the trial upgraded to enterprise.

Thanks!