What is the meaning of these red bars in git file difference

Question

There is a red bar after + sign. What is this ?

Answer 1

Potentially bad indentation. You may have used tabs when you configured Git to prefer spaces, or vice-versa.

Check git config core.whitespace; it might contain tab-in-indent, space-before-tab, or indent-with-non-tab. You should change it to suit your preferences if this isn’t really a mistake.