Posts are not there

I’ve got WP installed twice, in two different databases running on my site.. the structure is something like this:

mysite.com/contributions/blog

and

mysite.com/wordpress

The first one works properly in terms of links to the articles.

The second one gives me the default WP error page when I try to look at an article I’ve posted. The only thing different is in the General Options, which looks like:

WordPress address (URL): https://mysite.com/wordpress
Blog address (URL): https://mysite.com

Both use the same theme, and have .htaccess files for the permalinks on both.

Thanks for your help,