Updated on May 4, 2016
Reduce the page size - Search Engines are not particularly fond of pages bigger than 2 megabytes. The engine will give the page lower priority as the accessibility factor is at stake.
Too many file requests - A lot of file requests indicate tax more the speed of which a page is being opened. Individual requests can be seen in a waterfall graphic with tools such as Pingdom and a lot of them can be optimized by combining different elements of the same type together.
URL is SEO friendly - Search engines better understand the topic covered in a page if the URL is relevant to it and does not contain any other unnecessary symbols.
Exact keyword not found in this URL - When you navigate to a specific page, the URL should contain a keyword that helps the engine understand it. This error can come up when you are checking the homepage of your website - this is perfectly fine.
No underscore in URL - Underscores are worse performers than hyphens when it comes to separating words in URLs in a Search engine friendly kind of way. You can of course not use spaces between your words but this only works for shorter domains consisting of two or three words.
Page is close enough to top-level domain - The closer a page is to the root of your website the more valuable that page is to search engines. An article which can be opened via domain.com/article will score better than an article located at forum.domain.com/archive/2016/article.