Wordpress: wp-admin Page showing Blank even changed the theme name

Question

I have wordpress website. But it have occurred some bugs after migrating website. When I try to login by redirecting the page wp-admi, page showing blank. I've resolved this error temporarily. Means, I've solved this by changing the active theme name. When I changed the active theme name then this trick worked and I could login with wp-admin. But when I logout from admin and try to login again it gives same problem that is showing blank page. Every time I've to change active theme name. I want to remove this problem permanently.

Answer 1

there seems to be a php syntax (; forgotten, <? opening tag without php, etc...) bug in your used theme.

you have to find it (remeber what was edited last?) repair it, and then you can use the theme again.

Answer 2

This problem may be caused due to there is some space in top or bottom of function.php.

So, my advice is to just check your function.php and remove any spaces at the top or bottom of the page