Are 404 errors common ???

[RobertClive]

Hi

Some of my friends' sites are having this 404 (Required but not found URLs) errors now and then, which he can find out in his error logs.

Is it something he should be worried of or is it a common error?

 

[HostNurse]

404 error is a normal part of the web and it means and when you see this error it means the page page does not exist or unavailable. You can even customize your own 404 error page.

 

[larrygrakh]

It's normal of course except the case when you are sure that page is definitely exist.