I had this same problem after a Windows update around 8/15/2019.
I unplugged my usb, uninstalled e-licenser from add/remove programs, restarted, DL’d and reinstalled e-licenser, ran the maintenance, plugged in usb, registered all through e-licenser, closed e-licenser, launched Cubase 10 Pro to find full functionality and no error.
Man, Steinberg sucks.
haha.