What do you struggle in Fan Fics?

[Quilava42]

I written this thread at another forum website, so I thought that I wanted to make this thread here.

So, when writing Fan Fictions, what strucks out to you that you have problems with? The whole plot of the story? The way you write it or how it's going? Or the characters? I mean, what's that only weakness you have towards writing them?

This thread's made to let others sought your reasons and try to relate them so they can help you. This can maybe help you get the idea of what to do when reading other comments.