The relation under the extended data type (EDT) 'ItemId' must be migrated to table relation.

 How to resolve this BP warning in D365

The relation under the extended data type (EDT) 'ItemId' must be migrated to table relation.

Consider using EDT relation migration tool.

First of all, you need to define a relation from your table to InventTable. 

In that relation, you will add field ItemId. On that relation field, there is property named Source EDT. In that field, write ItemId.

if still error pesits set Ignore EDT relation to YES in the table field