Merger the albums give rise to system breakdown

I am already settling most problem about translate,but it appear a new problem today,when I merger two albums,the system is breakdown,it return a statement
“Cannot modify header information - headers already sent by (output started at /home/upbvw5swma/domains/artchina.com/public_html/wp-content/plugins/buddypress/bp-activity/bp-activity-screens.php:1) in /home/upbvw5swma/domains/artchina.com/public_html/wp-includes/pluggable.php on line 896”
and then I try to reinstall remedia,it can not be going,forntpage can not be open,it say"{BLOCK_TITLE}BuddyPress Activity{/BLOCK_TITLE}
Fatal error: Class ‘RTMediaModel’ not found in /home/upbvw5swma/domains/artchina.com/public_html/wp-content/themes/Msocial/gavern/widgets.buddypress.phpon line 79",
I don’t know how to solve the preblem,please tell me how to do,thanks

Hi @futures,

Regarding the merge album issue, we are not able to replicate the same at out end. And for your other issue, it seems like issue is with the widget of the theme that you are using.

Can you provide more details regarding the same or access to your site ? you can send it to [email protected]