We purchased the Dr. Web Antivirus solution for 2 of our Plesk 7.1.6 installations. When we recieved the key files, we were instructed to upload the keys via the Pleskcontrol panel.
Every time we tried, Plesk informed us that the file did not contain a valid key file.
To resolve the problem, we finally installed the key file manually, by copying the key file to the /opt/drweb/drweb32.key and then restarting Dr. Web using
service drwebd restart.
The above solved the problem on both, a RedHat 9 and RHEL 3 box.