Thanks for the reply.
I’m running Windows 10 and Bisq 1.2.5 (I’ve also been running Bisq since > 2 years on a Mac so I know how it should behave). The app appears and just becomes a white window. No firewall message since the first time I ran it, just the white window. When I’m running a Bitcoin Core node in parallel, the usual warning about syncing also comes up, and it goes away when I say ok. The app does not shut down until I click the window close X, but then it exits neatly with the same message as usual.
I can’t find any bisq.log in the directory C:\Users<***>\AppData\Local\Bisq or its subdirectories.