Rock Star Theme – Cannot Customize

I am using the free version of the Rock Star Theme. It was working fine, then suddenly stopped working and I lost all the changes I made. The problem is that when I click to customize the theme, I get an error message and can't see the customize menu. I contacted my web hosting company (1and1), they were unable to fix and said that the following error message came up: "Here is the error message that comes up when trying to customize the theme:" Warning: in_array() expects parameter 2 to be array, string given in /homepages/39/d113987024/htdocs/clickandbuilds/ProsadBeta769959/wp-content/themes/rock-star/inc/customizer-includes/sanitize-functions.php on line 108 I was going to buy the pro version, but having second thoughts now. website is: www.freedomcry.com Please keep in mind, I am a musician, not a developer, so simple/easy to follow instructions would be preferred. Thank you.