It is possible there is something on the server that is throwing an error.
We need to examine the log file from the server to find out more.
Could you perform the following steps please:
1. Log into your FTP site and edit wp-config.php
2. Set the following values (add the lines if they don’t exist):
define( ‘WP_DEBUG’, true );
define( ‘WP_DEBUG_LOG’, true );
define( ‘WP_DEBUG_DISPLAY’, false );
@ini_set( ‘display_errors’, 0 );
3. Return to the plugin and perform another search to trigger the error.
4. Now go back to FTP and send me the file /wp-content/debug.log
5. Return to wp-config.php and set DEBUG back to false (reverting the changes made in Step 2)
If you have any questions just let me know!