My software
My PHP version is : 7.2.XX
My MySQL version is: 5.7.28
My problem
I just updated to Mautic 3.0.1 from 2.5.3. First, everything seemed to work perfectly fine, new campaigns worked…
… but apparently, Mautic lost track of all old session cookie information = it doesn‘t recognize old/previously existing contacts‘ cookies anymore.
Since I‘m using Mautic also for things like Access Management for certain information hosted on my website, those contacts cannot access it anymore. (I cannot ask them all to reset their browser cookies.)
How can I fix this?
Can I somehow re-import those information? If yes, then how? Which table is this information in? …
Looking forward to a quick response. Time is pressing for me. 
Thanks!
– Martin