I use Paste Master as an advanced clipboard manager. It allows me to keep up to 90 items in my clipboard and also allows me to paste them unformatted so I don’t have to copy them to an ASCII text editor first. It would not come up one day and wanted to restart it without the OS (operating system). Under System Preferences, uncheck and check “Enable Paste Master” and that will restart it. Since it is a checkbox, it might appear to only take effect when the OS restart, but it takes immediate effect.