"pkexec mousepad %f" No Longer Works On The Latest Mousepad 0.6.1
I use pkexec mousepad %f as a custom action on thunar to call mousepad with root privileges on Arch Linux, recently mousepad was updated to version 0.6.1 which broke this function, the window no longer shows up after entering the password for root privileges.
I downgraded to 0.6.0 and it fixed the issue.