There is a specific process you must go through to update from 4 to 5
1) Do not deactivate ACF 4
2) Activate ACF 5
3) Upgrade Database (there should be a prompt to do this)
4) Deactivate ACF 4
If you do the above and still have issues the you need to open a new support ticket http://support.advancedcustomfields.com/new-ticket/
