@Tom Speirs
not sure if you changed a version, but I copied over my flash.ocx from my cabinet to the test machine.
and that is working
2:52:51.39 20-12-2023: PinballX Core - Version 6.03 x64
12:52:51.61 20-12-2023: Microsoft Windows 11 Home 64-bit (16GB)
12:52:51.61 20-12-2023: Loading Settings
12:52:51.61 20-12-2023: Initialize Component
12:52:51.66 20-12-2023: Initialize Display
12:52:51.69 20-12-2023: Testing Flash engine.
12:52:51.85 20-12-2023: Loading PlugIns
The wrong file is from 6.03. The correct flash.ocx is from a version of last year
I hope this helps