Duplicates ID on two models in Dynamics 365 for operations

Hi everyone,

Today, I would like to speak about Ids issue during environment update with Microsoft KBs.
I don't know if this solution is a best practice, but it works, and that's all I wanted at this time.

Update process contains two main steps : Preparation and installation.
During installation process, the system could notice you of a duplicate Id issue because a package (a custom!) has the same Id as a new one, present in the update.

In this case, you could : Export all code of your package, uninstall it, install the new standard package with the famous reserved Id, then create a new custom package for your customization and import your code in.
It's a bummer like the "Dude" will say, isn't it ? :)

So the shortest way could be : Stop IIS, edit descriptor of your custom package, change the ID, save and start IIS. Just to be safe, you could open Visual and compil all your application.

Launch a new installation of your previous preparation update, and Duplicate Ids issue will in theory vanish.

Happy Dynamics update!