redirect main site. again.

hello again,

I have a problem with redirecting main site to subfolder site…

i have wp multisite
ginbrin.com
ginbrin.com/si/

since a plugin i have installed messed up main site i would like to redirect it to ginbrin.com/si/

-or-

if you can help me not to redirect my ginbrin.com menu to ginbrin.com/en/
let me explain. if you go to ginbrin.com it loads fine. but if you click to any menu item you wil be redirected to ginbrin.com/en/something

Thank you for your help!