I went into the same problem and found a solution.
First, what’s the problem? When changing the Permalinks in Admin/Options/Permalink, I get this page error. All the site was then disabled. I then deleted the .htaccess file and the home page was working again. But the links didn’t work.
I then found out that the wp_options table contained an option: permalink_structure that had an option_value containing the file pattern (%blablah). I used the MySQL admin engine from Free and deleted this field in the row. Then everything went back to normal with the default permalink structure with pages numbers.
However, I still wonder what’s wrong in the first place. It may be due to the way Free has configured its Apache and MySQL servers.
