My neobux add-on disables itself and I cannot enable it. It's been running for a couple of months, but yesterday suddenly stopped. I've tried a lot but...

My neobux add-on disables itself and I cannot enable it. It's been running for a couple of months, but yesterday suddenly stopped. I've tried to remove it and then install it again and then restart(mozilla+PC) - didn't work. Tried to disable it (restart) and then enable it and then restart again - also didn't work. It is very weird!