I decided to try to find out the problem that might cause the infamous WRITERS BLOCK

I've found out some reasons I generally found. :

a. You are so focused to the end of the story too much instead of current flow.

b. You have another plot in your head and it disturbs your focus on your current story.

c. You left your fic fo so long until you forget the storyline you're supposed to write.

d. You have a life to live and ended up being too busy to sit in front of your PC to write.

e. The plot you are planning isn't developed enough than just a mere draft.

Which is your biggest case? Or do you have another cause?