I recently encountered a problem with Memo Pad. When I open it, there is no window. It appears on my taskbar, but clicking on its entry does nothing. If I hover over it, the preview appears like this:
Can you check the Window Rect in the ini file to see if it's values are on your screen?
Users\your user name\AppData\Roaming\Joyful Coder\Memo Pad\Memo Pad.ini
It is odd that the taskbar popup does not display the icon nor app name. When you say recently do you mean before release 19?