I take a look in my googletools and he show me in section ( page not found) a few errors ( www.mysite.com/%%name.htm or www.mysite.com/$&erros..) and google tell's me this pages he can't found on my site and show me this erros .Could I block this with robots.txt ? Thanks
I agree, you should find the errors and fix them, and until then I suggest you delete your robots.txt file from your server
Might be possible you had added these pages in your sitemap.xml, just try to remove these urls from your sitemap and then resubmit it