Cannot activate Revolution Slider

Problem:

I cant activate the slider plugin that the theme asked me to install.

I keep getting this error.

Parse error: syntax error, unexpected T_FUNCTION in /.../wp-content/plugins/revslider/inc_php/revslider_slider.class.php on line 851

Solution:

This problem may related with old php version on server. ThemePunch (plugin’s author) wrote:

“Please consider updating your server’s PHP to a more modern version in order to prevent similar issues with other WP products in the future. Your server is using a PHP Version < 5.3 , which is from July 2009.”

We also recommend to contact with server administrator because it’s not safe to work on such an old php version.

Also, if you are happy with one slider you can use the Main Slider and you don't need Revolution Slider

Main Slider should be the hero section of any page which has Slider hero section type.