SQL Server Agent job returns a failure status message after the job succeed. We have a sql server agent job which runs every day on sql server 2008R2. The job has been running for years and had no issues before; and nothing has been changed recently.

Two weeks ago, the job started sending a failed job email once every 2 or 3 days. It also logs a failed job status both on sql server agent job history  as well as event viewer. However, the job is successfully executed because we are getting a successful report from the application side all the time.  Can someone have any idea how to fix this issue?

Thanks
For me This looks a clash between job schedules. if the job is executing one day and fail the next day,there may be other job running that might contradict with this schedule. you might have to check all your job schedules and take appropriate action accordingly. 

This link might help you to check all the jobs schedules running in your server. 
http://www.sqlprofessionals.com/blog/sql-scripts/2014/10/06/insight-into-sql-agent-job-schedules/