Just had this issue upgrading from 2.15.*. It’s a known issue. Easiest way I found was to:
- Backup existing install of latest version (3.0.4 in my case)
- Install Piwik 2.17.0
- Delete config folder and move config folder from existing install to 2.17.0
— NB: I moved the whole config folder but you can just move config/config.ini.php - Visit site to perform database upgrade to 2.17.0
- Restore latest version and move the config folder from the 2.17.0 install back into latest.
- Visit site to perform databaseupgrade to latest install.
This process removes any need to manually mess around with SQL tables, because bad things can happen when you start dropping things…