walking behavior issues (Knee bends wrong)

Hello everyone

I animated a character, which can walk. He could do that, erverything worked. But one thing wet wrong: Unfortunately his knees move in the wrong direction. The character walks to the right, but his knees bend to the left. How can I change that? Last week everything worked fine, but when I reopened the program yesterday, my legs suddenly moved in the wrong direction. I don't know why. I changed nothing in the Programm since last week.

This is what my character looks like. The origins are already set.

And this is how the Character looks if he is walking:

Thank you for your help,

Ciao, Tanja