Too many redirects error

I’ve just started getting the “too many redirects” browser error on our dev site, and since the only way to escape it is to delete cookies, I can’t log in to try and fix it.
I have searched a number of previous cases but haven’t found a match for probable cause yet.
– We’re not (yet) using https or any settings/modules relating to it.
– We are using pathauto
– no recent manual changes to .htaccess
– we are using login-destination, but with a destination setting of – this was installed after we started getting the error (I still had a login at that point)
– we haven’t (yet) overridden the login form.
Logging in or trying to go to the home page with cookies always results in an attempt to load /?q=users/webmaster

Version 7.50

I have managed to disable pathauto via drush

Is there any way to debug the redirects which are happening?

Richard

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/22/feed