I'm getting an error message from googlebot saing:"robots.txt file does not appear to be valid" I guess the problem is when I have made a site redirection to my other site.I made this in the Google admin panel/webmasters/tools/change-address. can anyone tell me how can i fix this? Thanks in advance.
Does yoursite.com/robots.txt shows text? May be it redirects to index page of the new site. Then definitely your robots.txt won't be valid.
Google also makes it very clear that robots.txt needs to be a UTF8 encoded file. I'd confirm it is if you haven't already.