Well I just can say: I have this problem too. And I had this since years now but didnt really research it until now.
CentOS Linux 7.5.1804 (Core)
Plesk Onyx
Version 17.5.3 Update #57
Maybe that post helps to bump the thread to some devs. I as well suspect that updates might be the cause of...
Thanks!
I got my Licence from https://www.strato.de/apps/CustomerService...,
I uploaded it at "Start>Tools & Einstellungen>Lizenzverwaltung>Parallels Panel-Lizenzkey"
(but there was no checkbox to check "Replace the currently installed key with selected one")
Then went to "Keys abrufen"...
Same Problem here.
Strato Root-Server with Plesk on CentOS.
I updated Plesk to 11.5.30 today. Since Update I get:
"ERROR: Dr.Web Updater: key file not found !
See Dr.Web Updater log file for details." instead of the old Update-Email.
PS: I cannot say that I really understood all of the...