Urgent- rt media plugin cracks the site

for some reason today, the site started to give this below error:

Warning: session_start(): open(/tmp/sess_9mv25q5hju6qg0i8l2qdvup320, O_RDWR) failed: Permission denied (13) in /home/sitename/public_html/wp-content/plugins/buddypress-media/index.php on line 60

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/sitename/public_html/wp-content/plugins/buddypress-media/index.php:60) in /home/sitename/public_html/wp-content/plugins/buddypress-media/index.php on line 60

Warning: Unknown: open(/tmp/sess_9mv25q5hju6qg0i8l2qdvup320, O_RDWR) failed: Permission denied (13) in Unknown on line 0

Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0

I deactivaed the plugin and everything went back to normal. But I need the plugin to be working right now. Any help would be much appreciated. Thanks.