I can’t able to fully understand your problem but I have some solution may be useful to you. Your Problem is may be of WP_MEMORY_LIMIT.
in wordpress root folder open wp-includes/default-constants.php
on line define('WP_MEMORY_LIMIT', '32M');
change it to 64M or more.
It can also be problem of javascript or jquery.
Hi,
If you did not installed any plugins then fault is in your functions.php file of active theme. You need to delete last closing “?>” that is closing tag of php. Remove final closing tag of php.
In case if this if happening because of some plugin you need to find out exactly that plugin which is causing this by deactivating plugins one by one, And when you find that plugin which is causing this problem then do the same steps in all .php file of that plugin and remove final closing tag of php “?>”.
