CI 4.1.8 session issues

3 days later...

Cause of the problem was that CI session could not be written into database.
Simply session was too big, therefore on the next reload it could not be read.

https://codeigniter.com/user_guide/libra...ler-driver

When creating a `ci_sessions` table, use `mediumblob` instead of `blob`

blob - 65,535 bytes
mediumblob - 16,777,215 bytes