Hey I recently change the server to cloudfare servers but after one day i cannot login to my wordpress account, what is the issue?
I suspect this is because your SSL/TLS mode is Flexible, if it is, you should get a certificate on your server and switch that to Full (strict) which is likely to fix your issue and make your site secure.
Here is some more generic information:
The errors “The page isn’t redirecting properly” or “ERR_TOO_MANY_REDIRECTS” indicates a redirect loop between Cloudflare and your origin server. The easiest fix for this is to remove the redirect on your origin server. For a more detailed set of options, review the troubleshooting suggestions in this Community Tip. Let us know if you continue to see issues after trying the Quick Fix Ideas in the Tip, we’re happy to help further.