auditd linux

I am trying to read the audit.log on linux. I am using the input noted below; however, I keep receiving this error:

WARNING Module audit has no input files to read

<Input audit>
Module im_file
File "/var/log/audit/audit.log"
</Input>

Can somebody please explain to me what this error means and why I would be receiving it?

Thanks in advance for any help on this!