W3C Validator Error

Wow, only one error in the entire website, great job @catchthemes and @Sakin, thanks a bunch. The one error I was given was: Error Line 223, Column 43: Duplicate ID access. <nav id="access" role="navigation"> The last '>' in the second row is red-font, so I think they are indicating that that might be the error. The validator I used was validator.w3.org. Not too big of a deal, but just wondering why that is an error and how to fix it. Thanks