Q: active corners

Studio Brand wrote:

 

I use left bottom active corner for switching between windows of program. In macOS Sierra after switching OS activates other program and I need to press alt+tab for switch in the necessary program. El Capitan had no this mistake.

I am not sure I understand completely.

You have "Application Windows" for the bottom left corner:

Suppose, for example, that you have Mail as the active application and move the cursor to the hot corner.

This should open Mission Control with only the windows Mail. Right?

Are you saying that when you click on one of those windows, another program comes to the front, instead of Mail?

If this is the problem, all I can say is that I can't reproduce it, on either my two macs (both running Sierra).

So I assume this is caused by some software conflict, but is not a universal bug in Sierra.

Try creating a new user account and experiment. Do you see the same problem? (I strongly suspect the answer to be "no").

Next, try restarting in Safe Mode. I am not sure if Mission Control even works in Safe Mode; if it does, test.

In any case, restart normally again and retry. Chances are the cleanup that is done when booting in Safe Mode may have sorted this out.

Let us know.

Studio Brand wrote:

 

So.. I am in safari. Then I press Mail (standard program), then hot corner. I see mission control with one window of Mail. And I see Safari.

Safe mode not help.

Video: http://brand.dn.ua/1.mov

Thank you for the video. It certainly makes the problem perfectly clear.

When you say safe mode does not help, I suppose you mean  that after restarting normally the problem remains.

I need to ask you: does the problem also occur in safe mode itself?

Also, does the problem also occur in another user?

If the answers to the two questions are both "no" (as I suspect they are), please run Etrecheck (from your own account when booted normally) and post its report here.