Hello There,
You can increase the maximum execution limit by doing a number of ways to fix this error. The following:
A] Add the following line to your .htaccess file:
php_value max_execution_time 60
B] Add the following to php.ini
max_execution_time = 60
For further details and troubleshooting, please check out this page:
https://codex.wordpress.org/Common_WordPress_Errors