I upgraded to Lunacy 8.5.1 (Windows standalone installer) and it no longer launches.
Windows Event Log reports a missing dependency:
Description: A .NET application failed. Application: Lunacy.exe Path: C:\Program Files\Lunacy\Lunacy.exe Message: Error: An assembly specified in the application dependencies manifest (Lunacy.deps.json) was not found: package: 'OpenAL.Soft', version: '1.19.1' path: 'runtimes/win-x64/native/OpenAL32.lib'
As my day job is a .NET developer I was able to repair my install manually by extracting the missing file from the referenced nuget package and placing in the installation folder - but I thought I should report the issue in case no one else has done so.