Windows server installer does not load, once Upgrade Assistant has been pointed to the Win 11 ISO, despite CPU check and ISO mount

Hi,

So I am using this amzing utility to force a Win 11 upgrade on perfectly okay machines that do not meet the notional hardware requirement. These machine are on a network, so I am pulling down exactly the same Flyoobe & ISO from the server every time.

The process has been simple and completed on every single machine, except one, where the process goes exactly as with every other one, up to the prompt:

'Success - windows 11 installtion can now proceed. Please follow the instructions in the setup window'

...only that setup window never opens, on just this one machine.

I have run all updates, rebooted, tried another language ISO, etc etc - no game. There is nothing overtly 'blocking' it (eg antimalware), no error messages etc - it's just the process sinks without a trace!

Is there a known bug / issue / work-around? Can I use an alternative 'path' within Flyoobe, if so which / how? (Not my area of expertise...).

Thanks in advance, Damian.

Start by reproducing the Windows 11 upgrade flow on the affected machine after the CPU check and ISO mount, then compare it with a machine where the setup window opens. The issue is complete when the cause of the silent failure is identified and a verified workaround or fix is documented.

Written by the indexing model from the issue text.