I've also have this problem. I don't know if it occurred when I'm logging in the backoffice. I think i get it randomly. I'm starting getting these message when I've configured the 'Mail Alert'- module. I've changed the list of the E-mail addresses.
My email message i receive in my email is like :
---------
Hallo {firstname} {lastname},
Nieuw alarm bericht opgeslagen
OPGELET: er is een nieuwe waarschuwing in het logboek van de backoffice.
U kan deze bekijken via Geavanceerde Paramaters > Logs in uw backoffice.
------------------
Customers can still doing online shopping and pay.
---------------------
Update : "Disable all overrides" was 'Yes', now is it 'No'. (Turned off)
I don't if this helped. I will reply after 2 days of no getting log-warning message. Or I will reply if I still getting messages.
---------------------
Update 2: Didn't helped, still getting same message in my log and email
