larin555 wrote: I find it strange that you would have to edit default browser settings to use a CMS.
Default browser settings should work just fine. My post was not about a pristine clean browser right after installation e.g. fresh unspoiled browser.
It is that people might use various extensions, adblocks, etc. plus customize policy in browser settings to not accept cookies in some cases. I saw that prompt recently on localhost dev domain using a fresh browser with policy set to "strict" and an adblock (uBlock Origin), so what helped me immediately is to turn off protection for the domain. Quite possibly, some browser setting prevents cookies to be written.
That said, my other fix is similar to what KK suggested and perhaps won't work for you. I am attaching it here as an exception and favor (as it is part of the Ryazania pack and not distributed separately) because it won't break anything for anyone if a similar issue pops up for someone. However you'll have to connect this file in kfunctions.php or paste content there — I made it for my pack and will not take responsibility if used elsewhere.