Assigning image to Post-Type won’t work anymore: exceeded time?

Please set maximum execution time like below :

1 – Modify your php.ini file and set ini_set(‘max_execution_time’, 150);

OR

2 – Modify your site root .htaccess file and set php_value max_execution_time 150

Note : you can extend it as per your need. Here 150 means 2.5 minutes.