While creating a new ECMA2 MA, I was faced by this error: “Exception from HRESULT: 0x8023072A”

The only helpful info I found was this, buried deep in https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/WinArchive/[MS-UPSDBDAP].pdf

0x8023072A extension-dll-noimplementation
The management agent extension does not contain a class that implements the extension interface(s).

Turns out the DLL I was using (UNIFY Identity Broker) was an old ECMA one, not ECMA2.