The following problem occurred, which prevents Atlassian Bitbucket from starting:

• Home directory '/var/atlassian/application-data/bitbucket' is already locked by another running instance of Bitbucket.
  
  Please stop the other instance of Bitbucket and restart this instance.
  
  If you are absolutely certain that no other instance of Bitbucket is running, please remove the lock file '/var/atlassian/application-data/bitbucket/.lock' and restart this instance.