Parse error Newsline Joomla template

Please Help me,i have bought ThemeForest Newsline template
I have an error
Parse error : syntax error, unexpected ‘:’, expecting ‘;’ or ‘{’ in D:\xampp\htdocs\mysitename\plugins\system\helixultimate\src\Platform\Helper.php** on line 65

XAMPP
PHP Version 5.6.37
Database Version 5.5.5-10.1.34
Any help is appreciated.

Hi @suddyod,

Please contact the author of your purchased template, the template author will assist you.

How to contact an author to get support or for any technical query:

Thanks