Strange error during RDM publish with OnPublish

Hello community,

I’m working on an RDM project which has the OnPublish implementation. However, I am encountering an error whenever I try to publish a record. The error message from the Action History states:

The response message was:null and response error was 'errorMsg:Cannot get credentials for request.
'

I have checked all the database connections and the connection to the RDM web application on the runtime server, and there does not seem to be any issue in that regard.

Is anyone familiar with this error and could provide assistance? Thank you in advance.