Based on the error message that you mentioned, it seems to tell that there is something issue with the Primary Key column "ItemNumber" in your Dynamic 365 fin & ops table.
Please make sure you have set the "ItemNumber" primary key column as Read-Only and Optional, or Writable abd Required. In other words, you must set your Primary Key column "ItemNumber" to one of the following two possible properties in your D365 F&O table:
1. Read-Only and Optional
2. Writable and Required
Please consider configure the Primary Key column in your D365 F&O table as above, then try to add your data source again, check if the issue is solved.
Community Support Team _ Kris Dai If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.