eM Client was working just fine for me until this morning when I upgraded to the new version (8.2.1659). Now, everything seems to work fine with one big exception: when I click the “reply” button on the toolbar, nothing visible seems to happen in eM Client (it still lets me move from one email to another, for example), but I don’t get a “reply” window. The taskbar does show another window open - but the window is not seen. I can get there (to a new window) by using TAB. I have uninstall and reinstall. Rebooted several times.
Its working again now.