I hadn’t actually edited the .htaccess file. To make sure, I renamed the existing one and then changed-changed back and then saved my permalink structure in WordPress. The new .htaccess is:
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /coterie/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /coterie/index.php [L]
</IfModule>
# END WordPress
Also is it significant that the page that finally gives the error is /how-to-become-a-member/ which is not active and has been deleted?
Regards,
Mark