Currently the Expression field is not required, which makes it possible to click on Add without filling in the expression. The dialog then closes without any errors, which gives the impression that the condition has been created for the rule, when in fact no condition gets created.

Additionally, if you click Add and Add Another without filling in the Expression field, a message saying Entry successfully added appears, which is wrong and misleading.

The Expression field should be required when adding a condition to the rule, for both inclusive and exclusive rules, as it does not makes sense to create a condition without an expression.