Classic Shell: Forum

On Win8.0, pinning recent documents under the applications are not possible it seems at the moment with 4.1 and 4.2. It did use to work before as old pinned items are still present.

On a Win 8.1, this problem has not occured at the moment.

Tried uninstall/reinstall of Classic Shell without impact.

Any solution?

Pin that program to the taskbar and try to edit the jumplist from there. If that doesn't work either, most likely the jumplist file is corrupted. You can try deleting the file.
They are located in this folder: C:\Users\<username>\AppData\Roaming\Microsoft\Windows\Recent\AutomaticDestinations
You can simply delete all files if that's acceptable. You will lose all recent file data. Or you can try identifying which file belongs to your program. Open some file using the program and then see if one of the files gets updated (check if its timestamp changes). Then delete it.