The following problem occurred which prevents Atlassian Stash from starting correctly:

• Unable to create and acquire exclusive lock file '/var/atlassian/application-data/stash/.lock' for Stash home directory '/var/atlassian/application-data/stash'.
  
  Please ensure that the user running Stash has permission to write to this directory.
  
  If this is already the case, please check the logs for more information.