I upgraded to PD13, OS X 10.11.6 (El Capitan) with a Windows 8.1 vm with "Windows 7 Look" and Start8 running, and suddenly it requires two clicks to gain focus in a Windows app when switching from an OS X window. It did not do this in PD11 or PD12. I've rebooted and hard shutdown/restarted the VM, and it doesn't seem to help any.
Thank you for your suggestion, but it did not fix my issue. I did a full stop/start, installed the tools, then took the normal restart, then did a full stop/start, and it still exhibits the same issue.
Ok, Upon further investigation, the menu bar at the top will say "Windows 8.1" when it's in the initial (invalid) state, then upon second click it will say the application, so example: "Microsoft Visual Studio 2017" or "Notepad++ a free (GNU) ..." where that application now has focus. It seems like it actually selects the correct application for a quick flash and then loses focus.
I am seeing the same issue most of the time. It doesn't seem to matter whether I switch to the Windows application using the Command-Tab method, by clicking the application icon on the dock, or clicking directly on an application window. When this happens, I see Windows 7-64 is becoming the frontmost application. There are times when this doesn't happen. I'm still trying to track down what is different about those times. It does not seem to happen when switching between Windows applications. I'm running PD Pro 13, OS X 10.10.5 with Windows 7-64 bit as a client OS.