I did an import of accounts and contacts using Salesforce's Data Import Wizard.

I set up all the appropriate plugin settings on the Outreach side so that inbound accounts from Salesforce should sync and therefore be created in Outreach. And this is happening correctly with most accounts. But there are some accounts in Salesforce that are not in Outreach. 

I tried a manual pull of data from Salesforce to Outreach for these specific accounts, but I recieved this error message:


After a conversation with Outreach, their error logs indicate this is an issue on the Salesforce side. But I reviewed all of our validation rules (we only have 1 for accounts) and it doesn't appear to be causing the problem. Any ideas as to how to fix?