Problem in domain change

Hello,

Today, I tried to change the domain name of my existing forum. My forum was installed via Softaculous.

What I did:

In first step, I have copied all files to my new addon domain folder. Then I have changed the site url and cookies url in my forums admin panel. Then, I edited installation details in softaculous. I have replaced the old folder with new folder in directory path. and changed domain in url section.


What I get:

All pages are okay on new domain. But I can't log in to my new domain.

What's the error occured? Did I do anything wrong?

What's the solution now?

Thanks in advance.