When migrating from Inventory Server 3 to Inventory 6 the recommended and supported setup is to have the same collation on the InventoryDatabase (SnowDB), SnowLicenseManager Database AND the SQL instances they recede on.
So, when you need to upgrade your Inventory server there could be an issue if the SLM and Inventory doesn’t have the same collation. However, this differs from the collation of the master, msdb, tempdb etc. as the upgrade of Inventory 3 to 5 will create a new database with SQL default collation. This leaves you with a newer Inventory server running the Data Update Job where there is a collection mismatch between both databases AND the SQL Instance. Which can create problems.
Luckily there is a simple and easy fix.
Before starting the installation of the Inventory server 5 or 6 simply create a SQL user ex. SnowAdmin new Database named SnowInventory owned by SnowAdmin
And then set the collation to the same as the SnowLicenseManager database.
Then simply run the installation as normal and you will not have the problem with collection mismatch between the databases.