Sounds to me like your attempt to send the email timed out. Make sure the email information in the custom.config.php file is correctly filled out. Make sure the vendor directory is current with what is in github for the project. You can also use the command window to run “composer update” from the SI directory.
Also, in the custom.config.php file, you can set the zend.logger_level to DEBUG and create a logging trail in the tmp/log/si.log file.