I received the following error when trying to report for a deleted post. Actually, I first opened the report link in a new tab and then deleted that topic and when I wanted to continue giving papers...

BACKTRACE

FILE: (not given by php)
LINE: (not given by php)
CALL: msg_handler()

FILE: [ROOT]/includes/functions_module.php
LINE: 565
CALL: trigger_error()

FILE: [ROOT]/mcp.php
LINE: 345
CALL: p_master->load_active()