Simplify the following text for a Grade 16 native English-speaking person.
Original: While the Bloc persisted through revolts including the Hungarian Revolution of 1956 and the aftermath of the Warsaw Pact invasion of Czechoslovakia , its command economies experienced inefficiency and stagnation preceding the Bloc 's dissolution .
Simplified: While the Bloc persisted through revolts , such as the Hungarian Revolution of 1956 and the Warsaw Pact invasion of Czechoslovakia , its command economies experienced inefficiencies and stagnation preceding the Bloc 's dissolution .