update organization fails from Dynamics CRM CRM2016 to D365

I noticed that many people get error while upgrading organization from CRM2016 to Dynamics 365 .

There are mainly two reason for this

1. New Microsoft.Xrm dll not getting updated in GAC while installing Dynamics 365 update.
    I suggest GAC it manually this DLL

2. Duplicate record create in metadata table mostly in optionset value . Find duplicate in metadata table and delete from SQL through query