Error occurred: 404 – not found

Hi,

When I changed my site’s permalinks to postname:
/%postname%/

i got this error when opening any page or post: Error occurred: 404 – not found

I have tried to delete the .htaccess -file and to change the permalink-setting, clicked save and changed it again to postname and clicked save. After this the .htaccess-file is created again:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

But this does not help. I have also changed back to Twenty fourteen -theme and deactived all the plugins and created a new .htaccess -file after this. Still no success. I also tried to rename the plugin-folders.

Any ideas what to try next?