Hi,
Apologies for delay in response, if this still an issue and if this is an on premise local controller, see if below information helps:
Navigate to controller installation directory and open mysql prompt:
shell> cd <Controller_install_dir>/bin
shell> ./controller.sh login-db
User controller.bat if this is windows controller
mysql> select * from incident where health_rule_id =19683 and end_time is null;
replace 122222 in below query with value from incident id captured from above query output
mysql> update incident set end_time = 1473397200000, status = 'CANCELLED' where id = 122222;