https://bugs.winehq.org/show_bug.cgi?id=41354
--- Comment #13 from Rahim sb56637@gmail.com --- Thanks for the reply.
On my system, I had to drop UIAutomationCore.dll in ~/.wine/drive_c/windows/syswow64/ , not system32. This is after installing from: http://downloads.pdf-xchange.com/EditorV6.x86.msi
As for the original bug report here, it appears that the MSI installed version is slightly less buggy in that respect. But I did find a way to reproduce it. Place your mouse exactly in the spot where you see in the screenshot I'm attaching. (The pointer should be an open hand icon, which the screenshot utility didn't capture.)