When accessing admin, I get redirect loop

I’m having a problem with my installation after moving the site to a new host.

The front-end works fine, and you can go to /wp-admin if not logged in, showing the login form, but if logged in, going to /wp-admin gives a redirect loop.

I tried looking online for a solution, but all the solutions seem to be for those who can’t access the front-end, but have access to the admin.

I removed the .htaccess file, but that then gave me an error 500, so I put it back again.

I’ve also tried renaming the plugin and theme folders, but still get the same error.