Perhaps you're right. Also, the issue is two years old, so I'm closing it since it might already be fixed.

If anyone is still experiencing the issue, please leave a comment or create a new topic.

What do you mean by "focus"? Aero peek? Bringing the window to front?

It depends on your antivirus or security software. Contact their support service if you need more help with this.

The 1003 error means that the tweaker failed to run the injected code as part of the explorer’s process.
This can be caused by an antivirus, which denies access to explorer due to security concerns.
Try whitelisting the tweaker.

That's a different issue. See here:

https://tweaker.userecho.com/communities/1/topics/165-remember-explorerfolder-order

See also my reply here:

https://tweaker.userecho.com/communities/1/topics/110-order-lost-when-updating

v5.6.2 is not the latest version. The latest stable version is 5.7, and the latest beta version is 5.7.0.3. Both should work with Windows 10 version 1903. Please update to one of these versions and see if that solves the problem.

What do you mean by "won't run"? Are you getting an error message? If yes, what's the exact message that you're getting?

Also, what's the version of your 7+ Taskbar Tweaker?

OK, I'll close the issue for now. Let me know if the issue comes back.

If you still experience the issue, you can try the linked guide, "Who the hell killed my process?", to find out why the tweaker is being terminated on your computer. Since I can't reproduce it on my computer, unfortunately I can't do much other than speculate.