Error in RFC; 'Function module "/GRCPI/GRIA_USR_GET_DETAILS" not'

Background: I have setup my sandbox to do the End User Logon so that guest users can come in and create access requests. This was configured and tested and it was working.

Then, we connected the Active Directory system, and that is also working so that when I go in as an authenticated user (NOT END USER LOGON), and create an access request, the user data is pulled from Active Directory.

NOTE: First, we finished the EUL, then weeks later, we connected LDAP. Now I am reviewing and this happens.

So today, I start seeing this error that's in the subject line. I'm attaching a screenshot.

As the sandbox was configured and working, I haven't gone and changed anything except for the user data sources, which is pointing to LDAP.

I went and changed the user data sources back to what it was before, and I'm still seeing this error.

Not sure where to look because what info I have found appears to suggest a plug in version discrepancy.

We don't have the GRC plug in installed on the GRC system. (separate question - should we have it installed on the GRC system?)

So ... I need some help please - this one is eluding me.

Thank you.

Santosh