I find errors when validating pages with https://validator.w3.org

https://www.joomlart.com/forums/topic/i-find-errors-when-validating-pages-with-httpsvalidator-w3-org/

https://validator.w3.org/nu/?doc=http%3A%2F%2Fpurity-iii.demo.joomlart.com%2Findex.php%2Flayout%2Fnew-layouts%2Ffeatures-intro

Hello

I am trying to validate my website pages and I see a lot of errors. So I checked the demo purity pages and I also see many errors.

I go to https://validator.w3.org and I try to validate purityIII pages like this:
http://purity-iii.demo.joomlart.com/index.php/layout/new-layouts/features-intro

For example:
Error: The align attribute on the div element is obsolete. Use CSS instead.
From line 593, column 3; to line 593, column 37

Is this a problem? Please advise.