https://bugs.winehq.org/show_bug.cgi?id=45753
--- Comment #6 from Dmitry Timoshkov dmitry@baikal.ru --- (In reply to Rosanne DiMesio from comment #5)
I guess that the same incompatible change would happen during the Windows XP to Windows 7 upgrade.
I imagine you're right, but both the wineprefixes in question were set to XP and I did not change that. Forced upgrades did not come to Windows until Windows 10.
I'm afraid that using Wine implies the continues forced upgrade... Anyway, this needs a retest before throwing even more speculations, and the retest should be done with default Windows 7 configuration.