Option tab in template manager not working

hello,
I installed the hot clinic quickstart template but the option tab in the template manager is the giving the following error:

Fatal error: Class 'ConfigControllerHelper' not found in C:\xampp\htdocs\...\administrator\components\com_config\config.php on line 25

please how can I resolve this?

thanks.

Are you using right joomla : template version. There is template for j2.5 and j3.x

yes, I am using the j3.x template

If you copied site using ftp client it may be that some files transfer failed. Best option is to copy whole ...hot_start.zip and unpack it directly on server , that way you are sure all files are there