How to remove Soft 404 error in Webmaster

How to remove Soft 404 error in Webmaster

Today, when i have reviewed my website http://www.neotericuk.co.uk, i have
sen this Soft 404 error like the given below:
URL: http://www.neotericuk.co.uk/blog/?like_it=721
The target URL does not exist and your server is not returning a 404 (file
not found) error. More info.
Your server returns a code other than 404 or 410 for a non-existent page
(or redirecting users to another page, such as the homepage, instead of
returning a 404). This creates a poor experience for searchers and search
engines.