https://bugs.winehq.org/show_bug.cgi?id=54194
--- Comment #3 from François Gouget fgouget@codeweavers.com --- Note for myself: UIPI == User Interface Privilege Isolation https://en.wikipedia.org/wiki/User_Interface_Privilege_Isolation
Given that this happens while sending a broadcast this would happen whenever a "high integrity-level" system process is running and thus the target of our test broadcast messages. So the only way to avoid that would be to restrict our test to one of the "very specific set of allowed UI messages" but I'm not sure that makes sense for the test. Otherwise the test would have to ignore permission denied errors.
At least on Windows 7. Question is then: why don't we get this issue on newer Windows versions? Did MS drop UIPI? Or do we just never have high "integrity-level" processes running on newer Windows versions? Can we dump information on the process triggering the errors? (in user32:clipboard I had a hack to trace an hwnd's GetClassNameA() and GetWindowTextA() which helped identify the cause of some failures)