Thanks for your advice on this. From your advice at least I know that running Armory version is 0.96.5-beta-8730390989 together with the full 648 Gb blockchain of Bitcoin Core 27.0 (64 bit) is capable of working on Win 11.

As recommended I deleted the Armory database folder, but had the same error.

I also tried re-indexed the bitcoin core blockchain, and deleted the Armory database folder, but unfortunately the same error occured again at Scanning Transaction History at 59%.

A last resort will be to uninstall and reinstall both programs and see if that helps to get things working correctly.