This has been an ongoing problem for many years through many versions of the program, (currently running latest Bandlab). Periodically I will lose MIDI connectivity. The drivers are still shown and checked in the settings dialog. Playing a MIDI sequence works fine. I can even trigger MIDI by mouse clicking on the virtual keyboard in a VST. But playing the keys on my keyboard triggers no MIDI. I'm using a NI S49. The little Sonar keyboard in the Windows tray is not blinking.
Usually someway, somehow I will get MIDI working. At this time, i'm out of ideas and ready to throw my rig out the window. I've tried reinstalling the keyboard drivers, rebooting my PC, switching the MIDI input between my keyboard driver, All Inputs, Omni and None. All to no avail. Does anyone know how to fix this?
NOTE: Everything works fine in Ableton, so this does appear to be a Cakewalk problem.