It worked by accident, and it became broken by accident. Keeping two customization tools that have no coordination compatible is quite tricky. I might look into fixing it later, but it's not a priority.

Regarding older versions, you can find them here:

https://www.dropbox.com/sh/mcbychsh0xc1dvu/AAC7NwQTQ-tOTNL2BUZ_CwUua?dl=0

That's a great question, the "taskbar wasn't found" message should never show up, unless maybe you have some other taskbar customization tool that might interfere with the tweaker. If you find a way to reproduce the error message, let me know. Meanwhile, I'm closing this topic since there's not much I can do with it without a way to reproduce the problem.

Thanks for confirming. The issue should be fixed in v5.12.1.1 beta.

I will look into it, but from a brief peek, my guess would be that turning off the fix_hang_reposition advanced option might work as a temporary workaround. Can you please verify that?

It is a known limitation, and it is indeed not listed in the FAQ or the documentation. Currently there's no fix for it, only workarounds, such as enabling "Decombine: Active group" and having the group active while moving the mouse to the other side.

You're using StartIsBack/StartAllBack, right?
See the discussion here:

https://rammichael.com/7-taskbar-tweaker-on-windows-11-with-windows-10s-taskbar#comment-13026

Is it related to the taskbar or to the tweaker's options? The z-order is not something the tweaker controls, especially not with the main window which is mostly standard. Sounds like the problem is with your system, unless I misunderstood what you mean.

OK, so I'm closing it. If it happens again, please try to explain in a way that is easier to understand, maybe with a help of a video or screenshots.

Fixed in v5.12.

Unless you meant something else, there's a registry option for that:

https://www.tenforums.com/tutorials/104754-change-width-taskbar-buttons-windows.html