Hi parallaxmontero,
In the older version, the Kunena supported the crypsisb3 template, however, this template is not compatible with the latest version and has been removed.
If you want to show the forum as the older version we need to customize the template layouts.
It's many changes, so, you can not get the layout style as the older version.
1/Unzip and copy/paste the com_kunena folder into \templates\ja_playstore\html folder
2/ Add the following CSS file into the \templates\ja_playstore\css folder:
Hope this helps!