AIMZ checks the values you type or paste, and rejects values that break the rules for the field. A rejected value is marked in red, and you are told what is wrong.
Common reasons a value is rejected
Duplicate: An account number or a production code can only exist once in the project.
Wrong type: Text in a number field, or a date in the wrong format.
Invalid choice: The value is not in the drop-down list, for example a status that is not defined.
Locked field: The field cannot be changed at all.
How to fix it
Hover over the red cell to see what is wrong, for example "The account number already exists on another line".
Enter a valid value, or press Ctrl+Z (Cmd+Z on Mac) to undo.
Click Save changes.
Good to know
As long as a cell is red, the bottom of the table shows how many rows have errors, and you cannot save.
The rules are the same as before. The difference is that you now get an explanation instead of nothing happening.