You can deactivate all plugins via the DB - you'll probably have phpMyAdmin or something from your hosting provider. Look for a field called active_plugins and turn that to NULL.
If you still have problems logging in then you will at least know it's an infrastructure issue. Try /wp-admin/ and /wp-login.php check that's where the 404 actually is and you aren'...
I have a plugin called "WPS hide login" which changes the name of the login page. Could that be the problem?
Deactivate this plugin before you do anything else. It's unlikely that the issue is with htaccess, especially if you deleted it and nothing changed.
You might need to look if there is another htaccess file in the wp-admin folder.
I'd like to redirect in ht.access
To clarify, it's .htaccess, not ht.access.
You can do something like the following at the top of the .htaccess file, before the existing WordPress directvies:
RewriteRule (.*/)page/\d+/?$ /$1 [R=302,L]
The above issues a 302 (temporary) redirect for any URL of the form /<something>/page/<number>/ (trailing ...
You can "workaround" the issue with a redirect in .htaccess, although it's not clear why this double-domain-URL would be accessible in the first place.
So, we can redirect URLs of the form example.com/example.com/?cat=6 to example.com/?cat=6, which you then say is correctly redirected to example.com/category by WordPress.
For example, at the top of ...
a) Would that work, and b) would this code be an acceptable way of
But you should put the custom directive (the Redirect line) above the BEGIN marker, i.e. the # BEGIN WordPress line, because if not, then your custom directive will be gone when the WordPress rewrite rules are flushed/regenerated.
# your code here:
Redirect 301 /foo https:/...