Final Fantasy 7 Reunion: missions not available, missable why?

In Crisis Core Final Fantasy VII Reunion (FF7), you may encounter that some of your side quests or missions are missable. 

 

Now, if you're already in the middle of the game and were so absorbed in the story that you forgot about the side quests, we have bad news for you. There are some missions that are missable. If you have reached a certain point in the story, the following missions can no longer be activated:

 

1-2-1

2-1-1 to 2-1-6

4-3-1 to 4-3-6

6-2-1

7-1-1

8-2-1

You must have unlocked these side quests and ideally completed them before you start the Chapter 8 "Nibelheim" (Seven Wonders of Nibelheim). Since there is no chapter selection after the end of the game, you will have to unlock all missions again in a new playthrough. Unfortunately, the mission status is not transferred to the New Game Plus.