My b2evolution Version: 2.x

Am sorry to put it here all though I have find riht place for this error I wish I could adress it on right palce,
There are two things here I am not sure If they are related the when I clik send or subit botton after creating a commnet test post or things of that kind I fall on error page, that is server not found, and only root directory link is out out there , that is to say l
ook like this http://mysite/blog/.. with page cannot be display
let mi knw where I did wrong I inst. this yesterday,
Comming to generating stub file, after just click the generate file I got a blank page get in back to my backoffice found stubb file not generate plz help mi on these
Thank you
Meshack Tz