I'm not familiar with RemoteApp. The feature you're asking for requires investigation that I'm unlikely to do, sorry. I also believe that it's less related to the tweaker, since it's not about tweaking the taskbar, but about making it run/appear in a specific situation.

Perhaps asking in a forum such as superuser.com will yield some results.

About the source code of 7+ Taskbar Tweaker, it's not available, but again, I don't think that it can be helpful in this case.

Does it work when you run it manually? If it does, it's clearly a system issue which is unrelated to the tweaker.

Which version of 7+ Taskbar Tweaker are you using?

What is your Windows build number?

You're either using an old version of the tweaker, or an insider Windows 10 build.

Which version of 7+ Taskbar Tweaker are you using?

Also, please post the exact text of the error message, including the error code number.

Great, marking as solved :)

Should be fixed now. The issue was caused by the update checking mechanism and a server mis-configuration. Sorry for the trouble.

No perfect solution below, but see also:

http://rammichael.com/7-taskbar-tweaker/comment-page-22#comment-5167

http://rammichael.com/7-taskbar-tweaker/comment-page-27#comment-6537

Not an ideal solution, but you can try the multipage_wheel_scroll advanced option.
Then, you can hold+scroll+release to drag items between pages.

Closing since there's no much information in the report.

If that's still an issue and you can provide a way to reproduce the issue, please leave a comment.

The item that causes the issue is Edge, not Explorer. The tweaker is not able to restore the position of "modern" items, such as Edge, on the taskbar. Since Explorer is probably pinned, the tweaker gets confused and loses track of its original location.

See also:

https://tweaker.userecho.com/communities/1/topics/337-some-options-eg-grouping-dont-apply-immediately-for-modern-apps-in-windows-10