So, are you using the "Combine when taskbar is full" configuration? Because if you are, it's just not supported and I can close this topic.

I assume you're using the "Remove extra gap between items" option, which makes pinned items take less space. You can turn this option off, which will revert to the default system behavior and make the pinned items take the same amount of space as running programs.

The "Combine when taskbar is full" configuration doesn't play along with the tweaker's combining options, see:

https://tweaker.userecho.com/topics/329-decombining-options-dont-work-as-expected-with-the-combine-when-taskbar-is-full-configuration

If there's another problem, then please provide steps to reproduce it.

Thanks for the follow up. I tried to get to the root cause, but didn't find the reason for the failure. I do suspect, though, that the issue only happens when the tweaker is used together with Open Shell/Classic Shell. Good to know the workaround I used works.

The "Cycle through windows" option uses a Windows feature, which can also be used without the tweaker by holding the control key. I think the order of cycling is such that the most recently used windows come first. Currently the tweaker provides no extra control for the cycling order, I might look into it in the future.

Where can I donate

You can donate here. Thank you.

Great. I don't know why the issue happens, maybe an obscure Windows bug, but I changed the implementation such that the initialization should no longer be affected by it. You can update to v5.12.3.2 beta, please let me know if the issue occurs again.

Interesting. It looks like the operations to apply the disable_taskbar_transparency advanced option cause this. That's probably why no other users reported about it - it's not a commonly used option, and not all users report about all problems.

Can you turn it off and see if that fixes the problem?

OK, so it looks like something in SetOptions might cause it.

Here's a new build with debug logs in SetOptions:

https://www.dropbox.com/s/w5uvwykzbunveie/7tt_setup_v5.12.3.1_debug_3.exe?dl=1

I also added a slight delay for more deterministic output, initialization might take about five seconds instead of being instant.

Something very strange is going on there. The tweaker communicates with explorer and waits for a reply. The message goes through, but instead of a reply, the communication tears up early with an error. I have no explanation for this yet.

Here's a build with more logging. Please try it and attach its log, perhaps it can shed some light.

https://www.dropbox.com/s/471htj4ib417yo2/7tt_setup_v5.12.3.1_debug_2.exe?dl=1