Why doesn't moving up and down work in VIM?

Question

vim

Moving up and down with arrows and letters ( jk ) doesn't work.
At the same time, moving along the left and right arrows and the letters h l works fine.
How to fix?

Answer 1

Moving up and down with arrows and letters ( jk ) doesn't work.

in any file or in one particular one? Maybe this file consists of one single line? What does it say about him wc -l <имя файла>?