Identity SIEM integration

Hello all,
I’m trying the ability to parse events from Identity into CEF to pass it further to SIEM.
I’ve followed the instruction and the pdf walkthrough
but when I run the I receive the following error:

Unsuccessful call to Redrock/query API
Reponse.Message: Query has failed: Storage layer exception occurred
Reponse.Exception: No additional diagnostic information is available.

I would like to know what is this Storage layer, and how to handle this error.