dashboard is down: undefined variable and can't modify header

I create a site, tried to use one of the landing-page template and my admin area is down..
I have to delete the parent theme and upload it new 🙁

Notice: Undefined variable: deprecated in /www/htdocs/xx/xx/xxwp-content/themes/bizznis/lib/functions/options.php on line 152

Notice: Undefined variable: deprecated in /www/htdocs/xx/xx/xxwp-content/themes/bizznis/lib/functions/options.php on line 152

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/xx/xx/xxwp-content/themes/bizznis/lib/functions/options.php:152) in /www/htdocs/xx/xx/xxwp-admin/post.php on line 197

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/xx/xx/xxwp-content/themes/bizznis/lib/functions/options.php:152) in /www/htdocs/xx/xx/xxwp-includes/pluggable.php on line 1228

thanks
Monika