It's difficult for me to troubleshoot the problem since I don't have access to Outlook 365 for Enterprise. Also, it's quite surprising if 7+ Taskbar Tweaker causes such an incompatibility, it shouldn't affect other apps.

Perhaps try disabling all of the tweaker's options and see whether the issue goes away. If it does, try to find out which of the options causes the problem.

Thanks for letting me know, it should be fixed now.

You can get old versions of the tweaker here:

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

But even if installing v5.10 fixes your issue, I'd like to make sure the latest version works correctly for all users.

What doesn't work for you in v5.10.1? Are you getting any error message?

Fixed in v5.10.1.

Done in v5.10.1.

Should be fixed in v5.10.1.

Should be fixed in v5.10.1.

Should be fixed in v5.10.1.

Great, I'm glad that you solved the problem. Thanks for the donation, I appreciate it!