I think the original text (in Arabic) is a little bit confusing as it doesn't consist of sentences but rather of small chunks (given the fact that it is probably part of the internet jargon, usually elliptical and pithy). I added what I think might help in clarifying what I deduce is the context.
शीर्षक
It is about an internal search engine for the site
It is about an internal search engine for the site. When I see the text: "enter the search term", I enter the following search terms: scientific messages, teaching personnel and staff. Result: term not found.
'enter the search index' is better translated by 'enter search word(s)'
Also 'search indices': 'search words' as well as 'index not found' 'word(s) not found'