Excel export does not work

Hello,

My export to Excel does not seem to work.
Error:

Parse error: syntax error, unexpected ‘[‘ in /var/www/vhosts/46/165677/webspace/httpdocs/domain.com/wp-content/plugins/advanced-cf7-db/admin/class/PHPExcel.php on line 9

Code in line 9:
private $_types = [ ‘xlsx’ => ‘Excel2007’, ‘xls’ => ‘Excel5’ ];

There is a topic about this, but this one i 2 months old and offers no solution:
https://www.ads-software.com/support/topic/newest-version-1-4-2-export-errors/