WordPress Migrator "Maximum execution time of seconds exceeded" error
This message means that the allowed PHP max_execution_time set on your host via the PHP max_execution_time variable has been reached during the transfer process.
To resolve this problem increase the value of the max_execution_time variable to a higher number and restart the migration process. SiteGround Cloud hosting customers can follow the instructions in this article to increase the variable.
Changing the value of the max_execution_time variable is not usually allowed on shared hosting environments. If your website is hosted on a shared plan then you should check for and remove any unnecessary large files in the wp-content/themes and wp-content/plugins folders of your WordPress. Deleting unnecessary large files from these folders will decrease the amount of time it takes for the plugin to perform the migration and resolve the problem. SiteGround customers can use the Site Tools -> File Manager tool to look for such files and remove them.