Simplify the following text for a Grade 10 native English-speaking person.
Original: This distinction arose after Members of the Scottish Parliament complained that Scotland was the only country in the world where the potential existed for the citizens of a country to be unable to fly their national flag on their country 's national day .
Simplified: This difference arose after Members of the Scottish Parliament complained that Scotland was the only country in the world that could not fly its national flag on its national day .