Hard to say what may have caused this. It sounds like you weren’t having issues with other forums. We weren’t hearing similar reports from other members, so it might be one of those unexplainable technical hiccups 
Glad it is working for you now!
I guess I spoke too soon. No digest sent last night. I really don’t understand because I’ve received this digest every single night for the past several YEARS until now.
Well, that’s no good. Pesky mail servers, perhaps. Are you aware of other members talking about this issue as well? Usually, this is a community-wide issue when it happens.