no proposed insertion point

You are using a multirow taskbar, right? I cannot reproduce the issue.

Does the issue occur only when the tweaker is running? Does it occur when all of the options are off?

Perhaps you can track the option which causes the issue?

I am using a 4-row taskbar, but I don't think the number of rows makes a difference.

image of settings is attached

I don't see an image.

Also, could you please answer the questions from my previous comment?

To answer your questions:

Yes, multirow taskbar.

When Tweaker is NOT running, I can't move any of the taskbar buttons.

When I uncheck all of the Tweaker options, I get the same symptoms (no insertion point)

As I said, I can live without the insertion pont, as what is most important is moving the buttons around . BTW, I typically have well over 10 Firefox windows open and I like to arrange them alphabetically by name. I can name each window using the FireTitle extension.

These are the settings I typically use. The attachment didn't work before because I had the image in a Wordpad file.

I am running Windows 10 Professional (64-bit) (with anniversary update)

When Tweaker is NOT running, I can't move any of the taskbar buttons. When I uncheck all of the Tweaker options, I get the same symptoms (no insertion point)

That doesn't make sense. You should be able to reorder the taskbar buttons when the tweaker is not running - that's a feature of Windows. Also, having the tweaker running without enabled options should not have any effect.

In order to investigate the issue, I need a way to reproduce it. As of now, I couldn't do that with your tweaker settings.