I migrated my website via backup and upload to a new server with a different sever IP. When I try to login to the ACP, it logs me out and show this error "Your IP address does not match this session. Help".

I can only login to the ACP using constant "\define( 'BYPASS_ACP_IP_CHECK', true );"  I tried clearing the system cache which did not fix it. Is there a method I can use to fix this issue?

Did you clear your browser cache and your site cookie on your browser?

I do recommend trying this first

4 hours ago, media said:

Did you clear your browser cache and your site cookie on your browser?

I do recommend trying this first

Yes, that did the trick. Thanks 🙏.

Unfortunately the issue is still there. I can login but when I click a tab it logs me out.

Same question as in the other topic there. Do you have any caching running on your server at all? I

50 minutes ago, beats23 said:

Unfortunately the issue is still there. I can login but when I click a tab it logs me out.

If it first worked fine as per your previous post above and the issue started again, it looks your IP is changing while you are in session, which is causing the issue. 

Have a look at the ACP IP Checks section in the following guide.

On a side note, id your ISP using IPV6?  Are you using CloudFlare or some reverse proxy?

Edited January 15Jan 15 by Miss_B

Yes, my website is on Cloudflare. I'm only able to log in using the constant file. I now have a new issue. I created a backup of the website and upgraded it to V5, for which the login works fine on localhost. I uploaded that copy to my live test site, and now I can't log in via admin or front end. The constant file doesn't work. The error says, "A configuration or server error has occurred" Is there a table in the database I can empty or a mod I can use to regain access to the admin login on my live test site?

You will want to restore your backup you took prior to upgrading to version 5. If you're having problems with your hosting configuration on version 4, it is not recommended to do a jump to beta software of a major release.

CloudFlare is a reverse proxy so you will need to enable "Trust IP addresses provided by proxies?" in ACP -> System -> Advanced Configuration. This will tell the software to use the client IP address supplied by the proxy headers (aka the users actual IP address), rather than the IP address of the client browsing (CloudFlare's IP address).

Hi, no, I'm not upgrading my live working v4 site to V5 beta. It's too risky at this stage😀. I made a copy of the live site and then upgraded the copy version to v5 via localhost to ensure all the features my site depends on are working. I think I had that lockout issue because I upgraded via localhost. I don't have lockout issues when I upload the copy to the web and do the v5 upgrade there. Thanks for the info about Cloudflare. I didn't know Cloudflare was a proxy. That's why my IP would change whenever I refreshed the browser when viewing the IPS who's online page.

I now have a new issue. Only my admin account, admin 1, can access the website. No other admin account can log in via front and ACP. I get the A configuration or server error has occurred. This is not my server issue; I can log in to ACP fine with admin-1. Plus, my v4 site is on this server, which works fine.

That message would indicate its coming from the server, not the software. So you would need to check your server error logs

2 hours ago, beats23 said:

I now have a new issue. Only my admin account, admin 1, can access the website. No other admin account can log in via front and ACP. I get the A configuration or server error has occurred. This is not my server issue; I can log in to ACP fine with admin-1. Plus, my v4 site is on this server, which works fine.

Can you check your server error log if there are any recent messages logged in there pertaining to this?