Why would bogofilter use different data file?

[Maciej Pilichowski]

Hello everyone,

  I lived happily with openSUSE 13.2 and bogofilter 1.2.4 until I 
migrated to openSUSE 15.3 with the same bogofilter but packaged 
differently.
  Previously I used .db file for data, I still have this file, but now 
bogofilter ignores it, instead it uses .kct file.
  As the effect it is still learning, and all mails are classified as 
unsure (for example "X-Bogosity: Unsure, tests=bogofilter, 
spamicity=0.520000, version=1.2.4").
 
  What could have caused switch to .kct file and how to activate 
old .db file? For the record I used and still use KDE3 KMail.

  Thank you in advance.

Cheers,
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