Error when populating Open Messaging Integration picklist values

Anyone else getting the error below when you click the 'Retrieve Options' button in the config page of the Genesys Cloud for Salesforce External Routing (Unmanaged) package?

Managed Package Version 4.20
Unmanaged Package Version 1.6
Error message: Failed to retrieved Genesys Cloud external routing options: Failed to populate picklist values for External_Routing_Request__c.Open_Messaging_Integration__c