Floodlight Cam Plus bulbs

I'm hoping there is an easy fix.  The camera itself still work, so this isn't a power issue.  There had been a couple power issues (this was mentioned as an issue in some other posts).  The problem is the lights themselves aren't turning on, though the app thinks they are.  The schedule is still set the same, on at dusk, of at 11:00 pm, then only triggered by motion.  The lights simply aren't going on.  Supposedly the bulbs shouldn't be 'dead'; i haven't had this for 20 years.  Is there some other known issue going on?  Or, are these bulbs dead for some reason, and I can replace them?