https://bugs.winehq.org/show_bug.cgi?id=41361
--- Comment #10 from Zebediah Figura z.figura12@gmail.com --- Found the bug—the problem is that the custom action DLL is removed before the custom action tries to execute. I'm not sure why this is traced as a WARN, or why it doesn't return an error...
In any case, this is a legitimate bug and a duplicate of 44036—standard actions need deferral.