Im getting Fatal error when i try to login to Wordpress Admin

I’m using Perth Theme,because of the unique design,Everything was nice but now when I try to login to my Wordpress admin,I’m getting

Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 1024 bytes) in /home/oglae/public_html/wp-includes/class-wp-user.php on line 744

Can you guys kindly suggest me how to fix this one?
I manage changes in php.ini by increasing the memory limit from 128 M to even 512 M.But it’s not solving my issue.

Thanks and looking for a fix from here soon

Dear Bala,

Please see this thread which might help you.