SLA Source for Trade Sales Issue Event Type is not activated

Summary:

Our project has a requirement to derive one of the COA segments based on a sales order EFF. Since sales order EFF are not present as the SLA sources, I am mapping them to RMCS EFF and using RMCS EFF as the SLA source i.e., Revenue Management Extensible Line Char Attribute 41.

But system is giving the below error:

The condition of account rules assigned to journal lines uses sources that aren't assigned to the event class. (XLA-870598). You must remove the source from the account rule conditions, or select a different account rule for assignment to the journal entry line.