OEM:Daily / Weekly Backups not happening

Issue : 
Daily incremental/ weekly full backups scheduled through OEM is not happening as scheduled.

Troubleshooting:

1) First check whether emagent is running or not on that database node?
    a) ps -efa|grep agent

        - confirms the agent is running.

    b) cd /home/oracle/OEM_GRID/agent10g/bin/
       ./emctl status agent

       - The output says agent is up and running fine properly.

2) Checked whether agent upload is happening or not?
    ./emctl upload agent

    - ERROR. 
    May be the same thing is not allowing the backups to happen as scheduled.

Fix :
    cd /home/oracle/OEM_GRID/agent10g/bin/
    ./emctl stop agent
    ./emctl clearstate agent
    ./emctl start agent
    ./emctl upload agent

After this, scheduled OEM jobs will run as expected.