I just activated upfront theme and try to edit. the site went a blank with "error" message

my website went to a complete blank with only “error” message.

I cannot access any of my site(s) including admin. I checked the error log from my FTP. It shows the log below.

Can you help me recover the site?

[01-Apr-2015 02:23:04 UTC] PHP Warning: Invalid argument supplied for foreach() in /home1/atlasoc1/public_html/lightcanvas.net/lc-website/plugins/pro-sites/pro-sites-files/modules/premium-themes.php on line 183

[01-Apr-2015 02:23:06 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /home1/atlasoc1/public_html/lightcanvas.net/lc-website/plugins/pro-sites/pro-sites-files/modules/premium-themes.php:183) in /home1/atlasoc1/public_html/lightcanvas.net/wp-includes/option.php on line 748

[01-Apr-2015 02:23:06 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /home1/atlasoc1/public_html/lightcanvas.net/lc-website/plugins/pro-sites/pro-sites-files/modules/premium-themes.php:183) in /home1/atlasoc1/public_html/lightcanvas.net/wp-includes/option.php on line 749