StorageLimitException: All execution engines are at maximum load.

Dear all,

I have encountered a problem that whenever I press a button on Appian, A Message box "The System Has Encountered and Error" shown.

When I check my log, I found that a warning line pops up after my actions.

com.appiancorp.suiteapi.common.exceptions.StorageLimitException: All execution engines are at maximum load. Cannot start process/simulation. Archive existing processes to free up space.

I have taken the following actions but still unable to resolve the issue:

1. Ensure there is sufficient Hard Disk space

2. Run checkpoint scripts

3. Run clean up scripts for engines, archiving process and logs

4. Restart Appian

Do you have any clues for this?

Thanks in advance.