Open the Window Manager settings and choose the keyboard setup. Select a shortcut of your choice, e.g. "Switch application". Either double-click on it or click the "Edit" button below (the bug occurs either way). Set it to a shortcut of your liking, e.g. Ctrl-O. Then double click again on it or press edit again on the same shortcut. On the resulting dialog, pressing the "Clear" button does nothing (other possibilities such as "Cancel"=do nothing, and "press another shortcut" = change setting work fine). After this failed clear attempt, even the "Clear" button below the shortcut list fails to work for this shortcut! The only way to actually clear that shortcut is to edit it again, change it to something else, e.g. Ctrl-P, and immediately afterward press the Clear button below the list. The fact that an ingenious user can find a workaround to eventually clear a shortcut does not make this bug less embarrassing... Thank you in advance for fixing!
In my case "Clear" in shortcut editing dialog actually clears the shortcut, but the shortcut list doesn't show it. Scenario: Open Window Manager Settings, Choose Keyboard tab, select action with attached shortcut. Click Edit. In edit dialog click Clear, the list still shows old shortcut, but the shortcut doesn't work. Close Settings, run it again. The list shows no shortcut. XFCE 4.12 on Linux Mint 18
Yes, Dawid Motyka, I confirm your finding. Indeed the Clear button does clear the shortcut, but the list in the dialog does not get updated. It only updates upon exiting and re-entering Window Manager Settings. We should retitle this bug to something like "Shortcut list not updated after clear button is pressed" All the best, Nicola Manini
Moving to proper component.
Still doesn't fixed: https://forum.xfce.org/viewtopic.php?pid=53030
Works fine here with master
Olivier Fourdan referenced this bugreport in commit 464e152297c75354c58f1661fc9aa6cf9d417706 settings-dialog: Clear shortcut in treeview https://git.xfce.org/xfce/xfwm4/commit?id=464e152297c75354c58f1661fc9aa6cf9d417706
Actually, it worked but did not clear the UI... Fixed now in master.