1. When you want to update new version please check carefully your current version
2. If you version below 6.3.3 you need update 


Otherwise your system will crash and never possible to update

Only solution remove all and fresh install.

#### PLEASE MAKE BACKUP YOUR WHOLE SITE WITH DATABASE PREVENT FROM YOUR SERVER MANUALLY. ###

Check the Video how easy to update: https://www.youtube.com/watch?v=3NEY3DI84yA

Thanks