I was recently told that an web app I had developed was returning an HTTP 405 error upon being freshly deployed. It took me way too long to realise that cause of the issue came down to missing files. Specifically, the complete folder structure had been deployed however the files at the top level web root were missing. These are files are rather critical.
They are the web.config
and global.asax
If you are seeing this error, ensure these files have been deployed correctly and aren’t corrupt as a first point of call.

For SEO HTTP 405
- Chrome: The page you are looking for cannot be displayed because an invalid method (HTTP verb) is being used.
- IE: HTTP 405 The website has a programming error. This error (HTTP 405 Method Not Allowed) means that Internet Explorer was able to connect to the website, but the site had a programming error.
- Edge: HTTP 405 error That’s odd… Microsoft Edge can’t find this page
Paul.