Google Search Console Errors

On Google Search Console it says:

When we tested a sample of the URLs from your Sitemap, we found that some URLs were not accessible to Googlebot due to an HTTP status error. All accessible URLs will still be submitted.

HTTP Error: 404 URL: /wisdom-038/ - Nov 11, 2016
HTTP Error: 404 URL: /wisdom-011/ - Nov 6, 2016
HTTP Error: 404 URL: /faq/10-why-no-free-trial/ -Nov 2, 2016

I want all wisdom posts and faq’s to be available. Can you tell me what is stopping googlebot from accessing them. How do I fix these errors?

Support Access for is available for four more days.
Thank you.