“The SharePoint item being crawled returned an error when requesting data from the web service. ( Error from SharePoint site: Value does not fall within the expected range. )”

We are getting this error
“The SharePoint item being crawled returned an error when requesting data from the web service. ( Error from SharePoint site: Value does not fall within the expected range. )” the crawling is happening ,but no results in when i search in the site .
We tried the following :

1.Reset the index

2.take the backup of a site collection and restored in the new site collection.

after trying the above steps aslo we are facing same issue .

The search is not happening for only 2 site collection out of 20 site Collections .

We checked in the Event Log and ULS logs nothing is there related to the search .

Please Help us .