Browser Caching Not Working Plus Broken Site

Browser Cache Error message
Warning: preg_match() expects parameter 2 to be string, array given in /home/buckspar/public_html/buckspartyvenues.com.au/wp-content/plugins/wp-hummingbird/core/modules/class-module-caching.php on line 50

Warning: Cannot modify header information - headers already sent by (output started at /home/buckspar/public_html/buckspartyvenues.com.au/wp-content/plugins/wp-hummingbird/core/modules/class-module-caching.php:50) in /home/buckspar/public_html/buckspartyvenues.com.au/wp-includes/pluggable.php on line 1174

Plus Hummingbird broke the site. Not sure which part did it. So i deactivated it.