I was just searing on the net again and found that wrong.htaccess file code also caused this error. I removed some possible lines and now search is working!!
These were lines which I removed, not sure what is the purpose of these lines?
RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ websiteadresshere/$1 [R,L]
This reply was modified 7 years, 6 months ago by raufaamir.
Based on your first desctipion of the issue, I would have suggested to check the .htaccess rules first. The rule you pasted there is to redirect all traffic from port 80 to the ‘websiteaddresshere’ URL. Usually these are used to redirect http to https traffic, but this rule does not seem to be correct, which explains the problem.