When upgrading CRM v8.2 to CRM v9, most of the developers pay attention to the deprecations coming with CRM v9 and hope the plugin/workflow code will work fine with CRM v9.
But there is a drastic change for "OwningBusinessUnit" field in following entities.
- InvoiceDetail
- OpportunityProduct
- QuoteDetail
- SalesOrderDetail
The data type of the "OwningBusinessUnit" field has been changed to Lookup type.(In v8, this was an Unique Identifier).
V8
If you have used the field "OwningBusinessUnit" in above mentioned entities in your code, it is the time to update your code for CRM v9.