SFDC OAuth Redirect Failure Error

Description description

If attempting to connect Marketo to Salesforce via OAuth 2.0, no authentication window is presented by Salesforce allowing for credentials to be entered, only showing “Redirect Failure”

Resolution resolution

Disable the “Require PKCE” checkbox in the Connected App during configuration of OAuth 2.0, prior to connecting Marketo via the Native SFDC Integration. Root Cause:
PKCE not supported by Marketo’s sync solution with Salesforce. This is documented in Adobe Experience League: https://experienceleague.adobe.com/en/docs/marketo/using/product-docs/crm-sync/salesforce-sync/log-in-using-oauth-2-0